Medial malleolar osteotomy in the treatment of osteochondral lesions of the Talus - incidence and impact on functional outcome: a retrospective analysis based on data from the German Cartilage Register (KnorpelRegister DGOU).

BACKGROUND: There has long been discussion regarding the impact of medial malleolar osteotomies (MMO) as an adjunctive treatment for osteochondral lesions of the talus (OCLT). MMO may improve the visibility and accessibility of the talus, but they also pose a risk of periprocedural morbidity. There is a lack of research about the prevalence and consequences of MMO in the surgical treatment of OCLT. METHODS: This study retrospectively evaluated data from the German Cartilage Register (KnorpelRegister DGOU) from its implementation in 2015 to December 2020. The impact of MMO on patient-reported outcome measures (PROMs) was investigated. Wherever possible, subgroups were built and matched using a propensity score which matched a group undergoing OCLT without MMO. Matching included age, sex, weight, localization of the OCLT, the international cartilage repair society (ICRS) grading, surgical procedure and preoperative symptoms using the Foot and Ankle Ability Measure (FAAM) and the Activities of Daily Living Subscale (ADL). RESULTS: The prevalence of MMO in the operative treatment of OCLT was 15.9%. Most of the osteotomies were performed in OCL of the medial talar dome (76.8%) and in more serious lesions with an ICRS grade of III (29.1%) and IV (61.4%). More than half of the osteotomies (55.6%) were performed during revision surgery. A matched pair analysis of n = 44 patients who underwent AMIC® via arthrotomy and MMO vs. arthrotomy alone showed no significant differences in patient-reported outcome measures (PROMs, i.e. FAAM-ADL, and FAOS) at 6,12 and 24 months. CONCLUSIONS: MMO are mostly used in the treatment of severe (≥ ICRS grade 3) OCL of the medial talar dome and in revision surgery. Functional and patient-reported outcome measures are not significantly affected by MMO compared to arthrotomy alone. TRIAL REGISTRATION: The German Cartilage Register (KnorpelRegister DGOU) was initially registered at the German Clinical Trials Register ( https://www.drks.de , register number DRKS00005617, Date of registration 03.01.2014) and was later expanded by the ankle module.

Early ACL reconstruction shows an improved recovery of isokinetic thigh muscle strength compared to delayed or chronic cases.

INTRODUCTION: The recovery of periarticular strength is a major criterion in return-to-play testing. The rationale of the study was to assess the impact of the delay of surgery (∆ between injury and surgery) on knee extensor and knee flexor strength of anterior cruciate ligament (ACL)-deficient patients six months after reconstruction. MATERIALS AND METHODS: In a retrospective cohort study, all patients with ACL ruptures between 03/2015 and 12/2019 were analyzed. Inclusion criteria were isolated ACL rupture without any associated lesions undergoing a reconstruction using ipsilateral hamstring tendon autograft and adherence to isokinetic strength testing before and at 5-7 months postoperatively. These patients were then clustered into three groups: EARLY reconstruction (∆ < 42 days), DELAYED reconstruction (∆42-180d), and CHRONIC (∆ > 180d). Knee extensor and flexor strength of the ipsi- and contralateral leg were analyzed by concentric isokinetic measurement (60°/s). Primary outcomes were the maximal knee extension and flexion torque, hamstrings-to-quadriceps ratio (H/Q) ratio), and the corresponding limb symmetry indices. RESULTS: n = 444 patients met the inclusion criteria. From EARLY to DELAYED to CHRONIC, a progressive reduction in postoperative strength performance was observed in knee extension (1.65 ± 0.45 to 1.62 ± 0.52 to 1.51 ± 0.5 Nm/kg resp.) and flexion (1.22 ± 0.29 to 1.18 ± 0.3 to 1.13 ± 0.31 Nm/kg resp.) strength on the ACL reconstructed leg. This general loss in periarticular strength was already apparent in the preoperative performance even on the healthy side. When controlling for the preoperative performance using ANCOVA analysis, EARLY performed significantly better than DELAYED (extension p = 0.001, flexion p = .02) and CHRONIC (extension p = 0.005, flexion p < 0.001). Also, there were significantly higher values for H/Q ratio in the injured leg across all groups where the H/Q ratio increased from EARLY to CHRONIC and from pre- to postoperative values. CONCLUSIONS: With respect to the force generating capacity when returning-to-play, it is advantageous to seek for an early ACL reconstruction within the first 12 weeks after the injury. The increasing loss of thigh muscle strength observed in delayed or chronic cases affects the injured and also the non-injured leg. LEVEL OF EVIDENCE: III, retrospective cohort study.

Discharging the medial knee compartment: comparison of pressure distribution and kinematic shifting after implantation of an extra-capsular absorber system (ATLAS) and open-wedge high tibial osteotomy-a biomechanical in vitro analysis.

PURPOSE: Young and active patients suffering early degenerative changes of the medial compartment with an underlying straight-leg axis do face a therapeutical gap as unloading of the medial compartment cannot be achieved by high tibial osteotomy. Extracapsular absorbing implants were developed to close this existing therapeutical gap. Purpose of the present cadaveric biomechanical study was to compare the unloading effect of the knee joint after implantation of an extra-articular absorber system (ATLAS) in comparison to open-wedge high tibial osteotomy (OW-HTO) under physiological conditions. The hypothesis of the study was that implantation of an extra-capsular absorber results in an unloading effect comparable to the one achievable with OW-HTO. METHODS: Eight fresh-frozen cadaveric knees were tested under isokinetic flexion-extension motions and physiological loading using a biomechanical knee simulator. Tibiofemoral area contact and peak contact pressures were measured using pressure-sensitive film in the untreated medial compartment. The tibiofemoral superior-inferior, latero-medial translation and varus/valgus rotation were measured with a 3D tracking system Polaris. Pressures and kinematics changes were measured after native testing, ATLAS System implantation and OW-HTO (5° and 10° correction angles) performed with an angular stable internal fixator (TomoFix). RESULTS: The absorber device decreased the pressure in the medial compartment near full extension moments. Implantation of the ATLAS absorbing system according to the manufacturers' instruction did not result in a significant unloading effect. Deviating from the surgery manual provided by the manufacturer the implantation of a larger spring size while applying varus stress before releasing the absorber resulted in a significant pressure diminution. Contact pressure decreased significantly Δ0.20 ± 0.04 MPa p = 0.044. Performing the OW-HTO in 5° correction angle resulted in significant decreased contact pressure (Δ0.25 ± 0.10 MPa, p = 0.0036) and peak contact pressure (Δ0.39 ± 0.38 MPa, p = 0.029) compared with the native test cycle. With a 10° correction angle, OW-HTO significantly decreased area contact pressure by Δ0.32 ± 0.09 MPa, p = 0.006 and peak contact pressure by Δ0.48 ± 0.12 MPa, p = 0.0654 compared to OW-HTO 5°. Surgical treatment did not result in kinematic changes regarding the superior-inferior translation of the medial joint section. A significant difference was observed for the translation towards the lateral compartment for the ATLAS system Δ1.31 ± 0.54 MPa p = 0.022 and the osteotomy Δ3.51 ± 0.92 MPa p = 0.001. Furthermore, significant shifting varus to valgus rotation of the treated knee joint was verified for HTO 5° about Δ2.97-3.69° and for HTO 10° Δ4.11-5.23° (pHTO 5 = 0.0012; pHTO 10 = 0.0007) over the entire extension cycle. CONCLUSION: OW-HTO results in a significant unloading of the medial compartment. Implantation of an extra-capsular absorbing device did not result in a significant unloading until the implantation technique was applied against the manufacturer's recommendation. While the clinical difficulty for young and active patients with straight-leg axis and early degenerative changes of the medial compartment persists further biomechanical research to develop sufficient unloading devices is required.

Patellofemoral cartilage defects are acceptable in patients undergoing high tibial osteotomy for medial osteoarthritis of the knee.

BACKGROUND: Patients suffering cartilage defects of the medial compartment with underlying varus deformity do benefit from high tibial osteotomy (HTO) even in the long term. Nonetheless, kinematic and geometric changes especially in the patellofemoral joint have been described. Purpose of the present study was to evaluate the influence of patellofemoral cartilage defects detected during the diagnostic arthroscopy and their influence on HTO's postoperative outcome. METHODS: Ninety patients with a mean follow-up of 10.08 ± 2.33 years after surgery were included. Patients were divided into four groups according to their cartilage status in the patellofemoral joint (A = no defects, B = isolated lesions of the patella, C = isolated lesions of the trochlea, D = kissing lesions). Functional outcome was evaluated before surgery and about ten years thereafter by relying on the IKDC, Lysholm, and KOOS scores. Radiological parameters were assessed pre- and six weeks postoperatively. RESULTS: In groups A to D, the HTO led to significant patellar distalisation in the sagittal view, with the mean indices remaining at or above the limit to a patella baja. All patients in all groups profited significantly from HTO (higher Lysholm score, lower VAS p < 0.001), patients in group D had the lowest outcome scores. Patella height negatively influenced outcome scores in group C (Blackburne-Peel-Index-VAS p = 0.033) and D (Caton-Deschamps-Index-Tegner p = 0.018), a larger valgus correction was associated with lower outcome scores in group D (Lysholm p = 0.044, KOOSpain 0.028, KOOSQOL p = 0.004). CONCLUSION: Long-term results of HTO for varus medial compartment osteoarthritis remain good to excellent even in the presence of patellofemoral defects. Overcorrection should be avoided. Distal biplanar HTO should be considered for patients presenting trochlear or kissing lesions of the patellofemoral joint. TRIAL REGISTRATION: DRKS00015733 in the German Registry of Clinical Studies.

The lack of retropatellar resurfacing at index surgery is significantly associated with failure in patients following patellofemoral inlay arthroplasty: a multi-center study of more than 260 patients.

PURPOSE: To evaluate the clinical outcomes of patients with a minimum 2-year follow-up following contemporary patellofemoral inlay arthroplasty (PFIA) and to identify potential risk factors for failure in a multi-center study. METHODS: All patients who underwent implantation of PFIA between 09/2009 and 11/2016 at 11 specialized orthopedic referral centers were enrolled in the study and were evaluated retrospectively at a minimum 2-year follow-up. Clinical outcomes included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, the Knee Injury and Osteoarthritis Outcome Score (KOOS), the Tegner Scale, the visual analogue scale (VAS) for pain, and subjective patient satisfaction. Pre- and perioperative risk factors were compared among failures and non-failures to determine potential risk factors. RESULTS: A total of 263 patients (85% follow-up rate) could be enrolled. The mean age at the time of index surgery was 49 ± 12 years with a mean postoperative follow-up of 45 ± 18 months. The overall failure rate was 11% (28 patients), of which 18% (5 patients) were patients with patella resurfacing at index surgery and 82% (23 patients) were patients without initial patella resurfacing. At final follow-up, 93% of the patients who did not fail were satisfied with the procedure with a mean transformed WOMAC Score of 84.5 ± 14.5 points, a mean KOOS Score of 73.3 ± 17.1 points, a mean Tegner Score of 3.4 ± 1.4 points and a mean VAS pain of 2.4 ± 2.0 points. An increased BMI was significantly correlated with a worse postoperative outcome. Concomitant procedures addressing patellofemoral instability or malalignment, the lack of patellofemoral resurfacing at the index surgery and a high BMI were significantly correlated with failure in our patient cohort. CONCLUSION: Patellofemoral inlay arthroplasty shows high patient satisfaction with good functional outcomes at short-term follow-up and thus can be considered a viable treatment option in young patients suffering from isolated patellofemoral arthritis. Patellar resurfacing at index surgery is recommended to decrease the risk of failure. LEVEL OF EVIDENCE: Retrospective case series, Level IV.

Measuring standing hindfoot alignment: reliability of different approaches in conventional x-ray and cone-beam CT.

INTRODUCTION: Currently there is no consensus how hindfoot alignment (HA) should be assessed in CBCT scans. The aim of this study is to investigate how the reliability is affected by the anatomical structures chosen for the measurement. MATERIALS AND METHODS: Datasets consisting of a Saltzman View (SV) and a CBCT of the same foot were acquired prospectively and independently assessed by five raters regarding HA. In SVs the HA was estimated as follows: transversal shift between tibial shaft axis and heel contact point (1); angle between tibial shaft axis and a tangent at the medial (2) or lateral (3) calcaneal wall. In CBCT the HA was estimated as follows: transversal shift between the centre of the talus and the heel contact point (4); angle between a perpendicular line and a tangent at the medial (5) or lateral (6) calcaneal wall; angle between the distal tibial surface and a tangent at the medial calcaneal wall (7). Intraclass correlation coefficients (ICC) were calculated to assess inter-rater reliability. A linear regression was performed to compare the different measurement regarding their correlation. RESULTS: 32 patients were included in the study. The ICCs for the measurements 1-7 were as follows: (1) 0.924 [95% CI 0.876-0.959] (2) 0.533 [95% CI 0.377-0.692], (3) 0.553 [95% CI 0.399-0.708], (4) 0.930 [95% CI 0.866-0.962], (5) 0.00 [95% CI - 0.111 to 0.096], (6) 0.00 [95% CI - 0.103 to 0.111], (7) 0.152 [95% CI 0.027-0.330]. A linear regression between measurement 1 and 4 showed a correlation of 0.272 (p = 0.036). CONCLUSIONS: It could be shown that reliability of measuring HA depends on the investigated anatomical structure. Placing a tangent along the calcaneus (2, 3, 5, 6, 7) was shown to be unreliable, whereas determining the weight-bearing heel point (1, 4) appeared to be a reliable approach. The correlation of the measurement workflows is significant (p = 0.036), but too weak (0.272) to be used clinically.

Long-standing pubic-related groin pain in professional academy soccer players: a prospective cohort study on possible risk factors, rehabilitation and return to play.

BACKGROUND: Despite being a common overuse entity in youth soccer, scientific data on risk factors, rehabilitation and return to play for long-standing pubic-related groin pain is still rare. The current prospective cohort study aims to evaluate potential risk-factors, propose a criteria-based conservative rehabilitation protocol and assess return-to-play outcomes among professional youth soccer players suffering from long-standing pubic-related groin pain. METHODS: Male soccer players with long-standing (> 6 weeks) pubic-related groin pain from a professional soccer club's youth academy were analyzed for possible risk factors such as age, team (U12 - U23), younger/older age group within the team, position and preinjury Functional movement score. All injured players received a conservative, standardized, supervised, criteria-based, 6-level rehabilitation program. Outcome measures included time to return to play, recurrent groin pain in the follow-up period and clinical results at final follow-up two years after their return to play. RESULTS: A total of 14 out of 189 players developed long-standing pubic-related groin pain in the 2017/2018 season (incidence 7.4%). The average age of the players at the time of the injury was 16.1 ± 1.9 years. Risk factor analysis revealed a significant influence of the age group within the team (p = .007). Only players in the younger age group were affected by long-standing pubic-related groin pain, mainly in the first part of the season. Injured players successfully returned to play after an average period of 135.3 ± 83.9 days. Only one player experienced a recurrence of nonspecific symptoms (7.1%) within the follow-up period. The outcome at the 24-month follow-up was excellent for all 14 players. CONCLUSIONS: Long-standing pubic-related groin pain is an overuse entity with a markedly high prevalence in youth soccer players, resulting in a relevant loss of time in training and match play. In particular, the youngest players in each team are at an elevated risk. Applying a criteria-based rehabilitation protocol resulted in an excellent return-to-play rate, with a very low probability of recurrence. TRIAL REGISTRATION: The trial was retrospectively registered under DRKS00016510 in the German Clinical Trials Register on 19.04.2021.

Isolated high tibial osteotomy is appropriate in less than two-thirds of varus knees if excessive overcorrection of the medial proximal tibial angle should be avoided.

PURPOSE: To perform a detailed deformity analysis of patients with varus alignment and to define the ideal osteotomy level (tibial vs. femoral vs. double level) to avoid an oblique joint line. METHODS: A total of 303 digital full-leg standing radiographs of patients aged 18-60 years and varus alignment [mechanical tibiofemoral varus angle (mFTA) ≥ 3°] were included. All legs were analyzed regarding mFTA, mechanical medial proximal tibia angle (mMPTA), mechanical lateral distal femur angle (mLDFA), and joint line convergence angle. Based on mFTA, varus alignment was categorized as "mild" (3°-5°), "moderate" (6°-8°), or "severe" (≥ 9°). Deformity location was determined according to the malalignment test described by Paley. Two osteotomy simulations were performed with different upper limits for mMPTA: anatomic correction (mMPTA ≤ 90°, mLDFA ≥ 85°) and overcorrection (mMPTA ≤ 95°, mLDFA ≥ 85°). If a single osteotomy exceeded these limits at the intended mFTA of 2° valgus, a double-level osteotomy was simulated. If even a double-level osteotomy resulted in deviations from the defined limits, the leg was categorized as "uncorrectable". RESULTS: Mean mFTA was 6° ± 11° of varus (range 3°-15°). A tibial deformity was observed in 28%, a femoral deformity in 23%, a combined tibial and femoral deformity in 4%, and no bony deformity in 45%. The prevalence of a tibial deformity did not differ between varus severity groups, whereas a femoral and bifocal deformity was significantly more prevalent in knees with more distinct varus (p < 0.001). Osteotomy simulation revealed that isolated high tibial osteotomy (HTO) was appropriate in only 12% for anatomic correction, whereas a double-level osteotomy was necessary in 63%. If overcorrection of mMPTA was tolerated, the number of HTOs significantly increased to 57% (p < 0.001), whereas the number of double-level osteotomies significantly decreased to 33% (p < 0.001). Isolated DFO was considered ideal in 8% for both simulations. Significantly more knees were considered "uncorrectable" by simulating anatomic correction (18 vs. 2%; p < 0.001). A double-level osteotomy was significantly more often necessary in knees with "severe" varus (p < 0.001). CONCLUSION: Less than one-third of patients (28%) with mechanical varus ≥ 3° have a tibial deformity. If anatomic correction (mMPTA ≤ 90°) is intended, only 12% of patients can be corrected via isolated HTO, whereas 63% of patients require a double-level osteotomy. If slight overcorrection is accepted (mMPTA ≤ 95°), 57% of patients can be corrected via isolated HTO, whereas 33% of patients would still require a double-level osteotomy. LEVEL OF EVIDENCE: III, cross-sectional study.

High tibial osteotomy increases patellofemoral pressure if adverted proximal, while open-wedge HTO with distal biplanar osteotomy discharges the patellofemoral joint: different open-wedge high tibial osteotomies compared to an extra-articular unloading device.

PURPOSE: Valgus high tibial osteotomy (HTO) and a recently introduced extra-articular absorber have been shown to efficiently unload the medial compartment of the knee. However, only little is known about the influence of these treatment modalities on biomechanics of the patellofemoral joint. The purpose of this study was to investigate and compare the impact of different HTO techniques and implantation of an extra-articular absorber on patellofemoral contact forces. METHODS: Fourteen fresh frozen cadaveric knees were tested in a specially designed knee simulator that allowed simulation of isokinetic flexion-extension motions under physiological loading. Mean contact pressure (ACP) and peak contact pressure (PCP) of the patellofemoral joint was measured continuously between 0° and 120° of knee flexion using a pressure sensitive film in the following conditions: native, after biplanar medial open-wedge HTO with 5° and 10° correction angle performing an ascending frontal osteotomy of the tibial tuberosity, and after implantation of an extra-articular absorber system (KineSpring®). Including a second testing cycle with a biplanar medial open-wedge HTO with 5° and 10° correction angle performing descending frontal osteotomy of the tibial tuberosity. Values after each procedure were compared to the corresponding values of the native knee. RESULTS: Biplanar proximal osteotomy leaded to a significant increase of retropatellar compartment area contact pressure compared to the first untreated test cycle (Δ 0.04 ± 0.01 MPa, p = 0.04). Similar results were observed measuring peak contact pressure (Δ 1.41 ± 0.15 MPa, p = 0.03). With greater correction angle 5°, respectively, 10° peak and contact pressure increased accordingly. In contrast, the biplanar distal osteotomy group showed significant decrease of pressure values (p = 0.004). The extracapsular, extra-articular absorber had no significant influence on pressure levels in the patellofemoral joint. CONCLUSION: HTO with a proximal biplanar osteotomy of the tuberositas tibia significantly increased patellofemoral pressure conditions depending on the correction angle. In contrast a distally directed biplanar osteotomy diminished these effects while implantation of an extracapsular, extra-articular absorber had no influence on the patellofemoral compartment at all. Consequently, patients with varus alignment with additional retropatellar chondropathia should be treated with a distally adverted osteotomy to avoid further undesirable pressure elevation in the patellofemoral joint.

Isolated revision meniscal repair - failure rates, clinical outcome, and patient satisfaction.

BACKGROUND: Failure of isolated primary meniscal repair must be expected in approximately 10-25% of cases. Patients requiring revision surgery may benefit from revision meniscal repair, however, the results of this procedure remain underreported. The purpose of this study was therefore to evaluate the outcome and failure rates of isolated revision meniscal repair in patients with re-tears or failed healing after previous meniscal repair in stable knee joints. METHODS: A chart review was performed to identify all patients undergoing revision meniscal repair between 08/2010 and 02/2016. Only patients without concomitant procedures, without ligamentous insufficiency, and a minimum follow-up of 24 months were included. The records of all patients were reviewed to collect patient demographics, injury patterns of the meniscus, and details about primary and revision surgery. Follow-up evaluation included failure rates, clinical outcome scores (Lysholm Score, KOOS Score), sporting activity (Tegner scale), and patient satisfaction. RESULTS: A total of 12 patients with a mean age of 22 ± 5 years were included. The mean time between primary repair and revision repair was 27 ± 21 months. Reasons for failed primary repairs were traumatic re-tears in 10 patients (83%) and failed healing in two patients (17%). The mean follow-up period after revision meniscal repair was 43 (± 23.4) months. Failure of revision meniscal repair occurred in 3 patients (25%). In two of these patients, successful re-revision repair was performed. At final follow-up, the mean Lysholm Score was 95.2 (± 4.2) with a range of 90-100, representing a good to excellent result in all patients. The final assessment of the KOOS subscores also showed good to excellent results. The mean Tegner scale was 6.8 ± 1.8, indicating a relatively high level of sports participation. Ten patients (83%) were either satisfied or very satisfied with the outcome. CONCLUSION: In patients with re-tears or failed healing after previous isolated meniscal repair, revision meniscal repair results in good to excellent knee function, high level of sports participation, and high patient satisfaction. The failure rate is slightly higher compared to isolated primary meniscal repair, but still acceptable. Therefore, revision meniscal repair is worthwhile in selected cases in order to save as much meniscal tissue as possible.

Focal metallic inlay resurfacing prosthesis for the treatment of localized cartilage defects of the femoral condyles: a systematic review of clinical studies.

PURPOSE: To systematically review the results of focal metallic inlay resurfacing prosthesis for the treatment of isolated cartilage defects of the femoral condyles. METHODS: A systematic electronic search of the PubMed database and the Cochrane Library was performed in April 2017 to identify studies that reported clinical or radiographic outcome of focal metallic inlay resurfacing prosthesis for the treatment of isolated cartilage defects of the femoral condyles. Included studies were abstracted regarding study characteristics, patient demographics, prosthetic device and location, indications and contraindications, and outcome measures. Outcome of interest included functional outcome scores, radiographic measures, complications, re-operations, and conversion to arthroplasty. The methodologic quality of the included studies was assessed with the Coleman Methodology Score. RESULTS: Six studies with a total of 186 patients met the inclusion criteria. Five studies were level IV evidence, and one was level III. The methodologic quality of the included studies was good, with a mean Coleman Methodology Score of 78. Two different implants were used: the HemiCAP® (five studies; 66% of study group) and UniCAP® (one study; 34%) implant. The mean age was 46-54 years, and the mean follow-up was 24 months to 7 years. Pre- and post-operative outcome scores were compared in all six studies, and five studies reported significant improvements at the final follow-up for all scores (objective und functional KSS, KOOS, WOMAC, Tegner, HSS Knee and Function score, SF-36 and SF-12 physical component score) except for the SF-36 and SF-12 mental component score. Progression of osteoarthritis was analysed using the Kellgren-Lawrence grading in three studies (30% of study group), with two studies reporting significant progression. The OARSI grading system was analysed in one study with no significant progression. The overall conversion rate to arthroplasty was 22% with considerable differences between the two implants: 9% for HemiCAP® and 47% for UniCAP®. CONCLUSIONS: Focal metallic inlay resurfacing prosthesis seems to be a viable option for a carefully selected group of patients. Significant improvement in knee function and pain was observed in most patients. Uncertainty remains with regard to progression of osteoarthritis because of conflicting results and inconsistent reporting. One out of five patients has to be converted to arthroplasty after an average of 4 years. However, compared to the UniCAP® implant, considerable lower conversion rates were reported for the smaller HemiCAP® implant. LEVEL OF EVIDENCE: Systematic review of level III and IV studies, Level IV.

Sport-specific outcomes after isolated meniscal repair: a systematic review.

PURPOSE: The purpose of this systematic review was to assess sport-specific outcomes after repair of isolated meniscal tears. METHODS: A systematic electronic search of the MEDLINE and Cochrane database was performed in May 2016 to identify studies that reported sport-specific outcomes after isolated meniscal repair. Included studies were abstracted regarding study characteristics, patient demographics, surgical technique, rehabilitation, and outcome measures. The methodological quality of the included studies was assessed with the Coleman Methodology Score (CMS). RESULTS: Twenty-eight studies with a total of 664 patients met the inclusion criteria. The methodological quality of the included studies was moderate, with a mean CMS of 69.7 ± 8.3. The mean patient age was 26 ± 7.2 years and 71% of patients were male. Mean preoperative Tegner score improved from 3.5 ± 0.3 to 6.2 ± 0.8 postoperatively. Comparing preinjury and postoperative Tegner scores, comparable values were observed (6.3 ± 1.1 and 5.7 ± 0.8, respectively). Return to sports on the preinjury level was achieved in 89%. Mixed-level populations returned to their preinjury activity level in 90% and professional athletes in 86%. Mean delay of return to sports varied between 4.3 and 6.5 months, with comparable results between professional and mixed-level athletes. The pooled failure rate was 21%. The failure rate was lower in professional athletes compared to mixed-level athletes (9% vs. 22%). CONCLUSION: This systematic review suggests that isolated repair of meniscal tears results in good to excellent sport-specific outcomes and a high return to sports rate in both recreational and professional athletes. The failure rate is comparable to systematic reviews not focusing on sportive patients. LEVEL OF EVIDENCE: Level IV systematic review of Level I to Level IV studies.

Customized post-operative alignment improves clinical outcome following medial open-wedge osteotomy.

PURPOSE: High tibial osteotomy (HTO) has gained more importance in the treatment of cartilage damage or osteoarthritis of the medial compartment with concurrent varus deformity. Concerning the extent of axis correction, various different views exist. The aim of this study was to evaluate the effect of the size of axis correction on functional outcome in patients undergoing a valgus HTO. METHODS: From 2005 to 2013, 156 patients with an underlying varus deformity and cartilage damages or unicompartimental osteoarthritis of the medial compartment were treated by HTO. Retrospectively patients were allocated into three different groups according to the degree of axis correction. For this purpose, three adjacent areas, respectively, comprising 5% of the tibial plateau were defined. Limits of those areas were set as follows: with the medial border representing the 0% point and the lateral border representing the 100 point, the three areas were separated according to their limiting intersection points (group A 50-55%, group B 55-60%, group C > 60%). For comparison of the functional outcomes, standardized measures and scores were used (pre-OP: VAS, Lysholm; post-OP: VAS, Lysholm, KOOS). Analysis of the pre- and post-operatively recorded X-rays was effected by means of a planning software (mediCAD, Hectec GmbH, Germany), and statistical analysis was carried out using SPSS Statistics 21.0 (IBM Corp., Armonk, USA). A p value of 0.05 was considered statistically significant. RESULTS: Thirty-nine patients were allocated to group A, 50 patients to group B and 67 to group C. Pre-operatively, patients in each group were of a homogenous constitution. In the groups A-C, HTO proved to reduce the VAS score and to increase the Lysholm score (p < 0.001). Regarding outcome parameters, group A showed significantly better results in terms of increased Lysholm (p = 0.049) and KOOS pain score (p = 0.043). In patients treated by HTO and ACI implantation for medial compartment lesions, the best results were achieved in group A which was of statistical significance in comparison of the Lysholm (p = 0.006) and VAS score (p = 0.045) of groups A and C. In this subgroup, the size of the post-operative valgus angle significantly correlated with the final VAS score (PC 0.364; p = 0.013), final Lysholm score (PC - 0.390; p = 0.007) and KOOS4 (PC - 0.356; p = 0.014). CONCLUSION: HTO for varus deformity in patients with concomitant cartilage damage or osteoarthritis of the medial compartment is a reliable treatment option with satisfying functional outcome. Precise pre-operative planning regarding individual factors in each patient is mandatory; a pathology-based extent of correction leads to a favourable clinical outcome and to a significant reduction in pain. LEVEL OF EVIDENCE: Retrospective cohort study, Level III.

Patellar tendinopathy in young elite soccer- clinical and sonographical analysis of a German elite soccer academy.

BACKGROUND: The prevalence of patellar tendinopathy is elevated in elite soccer compared to less explosive sports. While the burden of training hours and load is comparably high in youth elite players (age < 23 years), little is known about the prevalence of patellar tendinopathy at this age. There is only little data available on the influence of age, the amount of training, the position on the field, as well as muscular strength, range of motion, or sonographical findings in this age group. The purpose of the present study was to examine the above-mentioned parameters in all age groups of a German youth elite soccer academy. METHODS: One hundred nineteen male youth soccer players (age 15,97 ± 2,24 years, height 174, 60 ± 10,16 cm, BMI 21, 24 ± 2,65) of the U-13 to U-23 teams were part of the study. Data acquisition included sport specific parameters such as footwear, amount of training hours, leg dominance, history of tendon pathologies, and clinical examination for palpatory pain, indurations, muscular circumference, and range of motion. Subjective complaints were measured with the Victorian Institute of Sport Assessment Patellar (VISA-P) Score. Furthermore, sonographical examinations (Aplio SSA-770A/80; Toshiba, Tokyo, Japan) with 12-MHz multifrequency linear transducers (8-14 MHz) of both patellar tendons were performed with special emphasis on hyper- and hypo echogenic areas, diameter and neovascularization. RESULTS: The prevalence of patellar tendinopathies was 13.4%. Seventy-five percent of the players complained of pain of their dominant leg with onset of pain at training in 87.5%. The injured players showed a medium amount of 10.34 ± 3.85 training hours and a medium duration of symptoms of 11.94 ± 18.75 weeks. Two thirds of players with patellar tendinopathy were at the age of 15-17 (Odds ratio 1.89) while no differences between players of the national or regional league were observed. In case of patellar tendinopathy, VISA-P was significantly lower in comparison to healthy players (mean ± SD 76.80 ± 28.56 points vs. 95.85 ± 10.37). The clinical examination revealed local pain at the distal patella, pain at stretching, and thickening of the patellar tendon (p = 0.02). The mean tendon diameter measured 2 cm distally to the patella was 4.10 ± 0.68 mm with a significantly increased diameter of 0.15 mm in case of an underlying tendinopathy (p = 0.00). The incidence of hypo-echogenic areas and neovascularizations was significantly elevated in players with patellar tendon syndrome (PTS) (p = 0.05). CONCLUSION: The prevalence of patellar tendinopathy in youth elite soccer is relatively high in comparison to available data of adult players. Especially players at the age of 15 to 17 are at considerable risk. Tendon thickening, hypo-echogenic areas, and neovascularization are more common in tendons affected by PTS.

Comparison of the efficiency of an extra-articular absorber system and high tibial osteotomy for unloading the medial knee compartment: an in vitro study.

PURPOSE: The unloading effect of an extra-articular absorber system on the knee joint medial compartment was compared with high tibial osteotomy (HTO) under physiological conditions in vitro. METHODS: Seven fresh-frozen cadaveric knees were used to test isokinetic flexion-extension motions under physiological loading using a biomechanical knee simulator. Tibiofemoral area contact and peak contact pressures were measured using pressure-sensitive film in the untreated medial compartment. Pressures were measured after KineSpring System implantation and HTO (5° and 10° correction angles) performed with an angular-stable internal fixator (Tomofix). RESULTS: Implantation of the unloading device resulted in significantly decreased medial compartment area contact pressure (Δ0.02 ± 0.01 MPa, p = 0.001) and peak contact pressure (Δ0.3 ± 0.1 MPa, p = 0.001) compared with the first test cycle results in the untreated knee. HTO significantly decreased the pressure (p = 0.001). Compared with the first test cycle, HTO (5° correction angle) decreased the mean contact pressure by Δ0.03 ± 0.01 MPa and peak contact pressure by Δ0.3 ± 0.01 MPa. With a 10° correction angle, HTO decreased contact pressure by Δ0.04 ± 0.02 MPa and peak contact pressure by Δ0.4 ± 0.1 MPa compared with that at the 5° correction angle. CONCLUSION: Implantation of an extra-capsular unloading device resulted in a significant unloading effect on the medial compartment comparable to that achieved with HTO at 5° and 10° correction angles. Thus, implantation of an extra-articular, extra-capsular absorber could become the method of choice when treating patients with unicompartmental osteoarthritis that cannot be adequately treated by HTO because of their straight-leg axis.

ACL deficiency and varus osteoarthritis: high tibial osteotomy alone or combined with ACL reconstruction?

INTRODUCTION: This study investigates the mid- to long-term clinical and radiological outcome in patients with symptomatic varus osteoarthritis (OA) and deficiency of the anterior cruciate ligament (ACL) and analyzes whether there are differences between isolated high tibial osteotomy (HTO) or combined single-stage HTO and ACL reconstruction (ACLR). METHODS: 26 patients who underwent HTO alone (group 1) and 26 patients who underwent single-stage HTO and ACLR (group 2) because of varus OA and ACL deficiency were examined at a mean of 5.8 years (SD 3.6 years) post-operatively. Assessment at follow-up (FU) was performed using a questionnaire including clinical scores (Lysholm, IKDC) and the KT-2000 arthrometer to examine anterior knee stability. Radiographic knee alignment and signs of OA according to the classification of Kellgren and Lawrence (KL) were assessed pre-operatively and at FU. RESULTS: Eighty-one percent of all patients reported an improvement of pain and 79% an improvement of instability without significant group difference. Significant worse results were observed in group 1 for the Lysholm score (group 1: 69.4, SD 15.7; group 2: 78.3, SD 16.4; p = 0.020) and the IKDC score (group 1: 64.8, SD 13.0; group 2: 74.0, SD 15.6; p = 0.006). No group difference was found for the KT-2000 examination. A significant post-operative increase of radiographic OA could be seen in both groups without significant group difference (KL pre-operative: 2.3, SD 0.63; KL FU: 2.8, SD 0.74; p < 0.001). The radiographic leg alignment at FU showed a significant lower valgus alignment in group 1 (group 1: 0.4 degree, SD 3.3 degree; group 2: 2.1 degree, SD 2.1 degree; p = 0.039). The rate of post-operative complications was low with 4%, and no significant group differences were found. CONCLUSIONS: This study shows that HTO alone can improve pain and even subjective knee stability. Additional ACLR was in the mid term not associated with a higher increase of OA or a higher rate of post-operative complications in our study collective.

Association between patellar cartilage defects and patellofemoral geometry: a matched-pair MRI comparison of patients with and without isolated patellar cartilage defects.

PURPOSE: To compare the geometry of the patellofemoral joint on magnetic resonance images (MRI) between patients with isolated cartilage defects of the patella and a gender- and age-matched control group of patients without patellar cartilage defects. METHODS: A total of 43 patients (17 female, 26 male) with arthroscopically verified grade III and IV patellar cartilage defects (defect group) were compared with a matched-pair control group of patients with isolated traumatic rupture of the anterior cruciate ligament without cartilage defects of the patellofemoral joint. Preoperative MRI images were analysed retrospectively with regard to patellar geometry (width, thickness, facet angle), trochlear geometry (dysplasia according to Dejour, sulcus angle, sulcus depth, lateral condyle index, trochlea facet asymmetry, lateral trochlea inclination) and patellofemoral alignment (tibial tuberosity-trochlear groove distance, patella height, lateral patella displacement, lateral patellofemoral angle, patella tilt, congruence angle). In addition to the comparison of group values, the measured values were compared to normal values reported in the literature, and the frequency of patients with pathologic findings was compared between both groups. RESULTS: The defect group demonstrated a significantly higher proximal chondral sulcus angle (p < 0.001), a significantly higher distal osseal sulcus angle (p = 0.004), a significantly lower distal sulcus depth (p = 0.047), a significantly lower lateral condyle index (p = 0.045), a significantly lower Caton-Deschamps index (p = 0.020) and a significantly higher Insall-Salvati index (p = 0.010). A major trochlear dysplasia (grade B-D) was significantly more common in the defect group (54 vs. 19%; p < 0.001). Eighty-eight per cent of patients in the defect group demonstrated at least one pathologic finding, compared to 63% in the control group (p = 0.006). Two or more pathologic findings were observed in 42% of the defect group and in 19% of the control group (p = 0.019). There was no significant correlation between the localization of the chondral defects and the results of the measured parameters. CONCLUSIONS: Cartilage defects of the patella are associated with the geometry of the patellofemoral joint. In particular, a flat and shallow trochlea, trochlea dysplasia and patella alta seem to contribute to the development of patellar cartilage defects, which must be taken into consideration when planning to do surgical cartilage repair at the patella. LEVEL OF EVIDENCE: III.

Arthroscopic Transtibial Pullout Repair for Posterior Medial Meniscus Root Tears: A Systematic Review of Clinical, Radiographic, and Second-Look Arthroscopic Results.

PURPOSE: To systematically review the results of arthroscopic transtibial pullout repair (ATPR) for posterior medial meniscus root tears. METHODS: A systematic electronic search of the PubMed database and the Cochrane Library was performed in September 2014 to identify studies that reported clinical, radiographic, or second-look arthroscopic outcomes of ATPR for posterior medial meniscus root tears. Included studies were abstracted regarding study characteristics, patient demographic characteristics, surgical technique, rehabilitation, and outcome measures. The methodologic quality of the included studies was assessed with the modified Coleman Methodology Score. RESULTS: Seven studies with a total of 172 patients met the inclusion criteria. The mean patient age was 55.3 years, and 83% of patients were female patients. Preoperative and postoperative Lysholm scores were reported for all patients. After a mean follow-up period of 30.2 months, the Lysholm score increased from 52.4 preoperatively to 85.9 postoperatively. On conventional radiographs, 64 of 76 patients (84%) showed no progression of Kellgren-Lawrence grading. Magnetic resonance imaging showed no progression of cartilage degeneration in 84 of 103 patients (82%) and showed reduced medial meniscal extrusion in 34 of 61 patients (56%). On the basis of second-look arthroscopy and magnetic resonance imaging in 137 patients, the healing status was rated as complete in 62%, partial in 34%, and failed in 3%. Overall, the methodologic quality of the included studies was fair, with a mean modified Coleman Methodology Score of 63. CONCLUSIONS: ATPR significantly improves functional outcome scores and seems to prevent the progression of osteoarthritis in most patients, at least during a short-term follow-up. Complete healing of the repaired root and reduction of meniscal extrusion seem to be less predictable, being observed in only about 60% of patients. Conclusions about the progression of osteoarthritis and reduction of meniscal extrusion are limited by the small portion of patients undergoing specific evaluation (44% and 35% of the study group, respectively). LEVEL OF EVIDENCE: Level IV, systematic review of Level III and IV studies.

Risk factors for posterior lateral meniscus root tears in anterior cruciate ligament injuries.

PURPOSE: To identify risk factors for posterior lateral meniscus root tears (PLRT) in patients with a tear of the anterior cruciate ligament (ACL). METHODS: A database of 268 patients undergoing primary ACL reconstruction between 2011 and 2013 was used to identify all patients with isolated ACL tears and patients with an associated PLRT. Patients with other concomitant injuries and patients who underwent surgery >6 months after the injury were excluded. Univariate analysis was performed by comparing the two groups with regard to gender, age, age groups (<30 vs. >30 years), height, weight, body mass index (BMI), BMI groups (<24.9, 25-29.9, and >30), type of injury (high-impact sports, low-impact sports, and not sports-related), and mechanism of injury (non-contact vs. contact). Multivariate logistic regression was carried out to identify independent risk factors for PLRT and to calculate odds ratios (ORs). RESULTS: One-hundred and forty-two patients met the inclusion and exclusion criteria. Of those, 120 (85%) had an isolated ACL tear and 22 (15%) had an associated PLRT. No significant differences between patients with and without a PLRT were found for age, age groups, height, weight, BMI, BMI groups, and type of injury (p > 0.05). Univariate analysis revealed a statistically significant difference between both groups for gender distribution (p = 0.034) and mechanism of injury (p < 0.001), with male gender and a contact mechanism being more common in patients with PLRT. The sole independent risk factor for an associated PLRT identified in the multivariate logistic regression analysis was a contact mechanism with an OR of 17.52. CONCLUSION: An associated PLRT is more common in male patients and patients who sustained a contact injury. Patients with a contact injury mechanism have an approximately 17-fold increased risk for a PLRT compared to patients with a non-contact injury. Special attention for this injury pattern is therefore necessary in those patients, and early referral to magnetic resonance imaging or arthroscopy is recommended. LEVEL OF EVIDENCE: IV.

Posterior root tears of the lateral meniscus.

PURPOSE: To summarize and discuss the current knowledge on posterior lateral meniscus root tears. METHODS: A comprehensive review of the MEDLINE database was carried out to identify relevant articles using different keywords (e.g. "meniscus root", "root tear", "meniscus avulsion", "radial tear" and "lateral meniscus"). The reference lists of the reviewed articles were searched for additional relevant articles. RESULTS: Posterior lateral meniscus root tears are found in 7-12% of patients with a tear of the anterior cruciate ligament (ACL). Biomechanical studies have found an increase in lateral compartment contact pressure of approximately 50% after creation of a posterior lateral meniscus root tear. There is some evidence that the biomechanical consequences of these injuries are significantly influenced by the presence and integrity of the meniscofemoral ligaments. Clinical studies have found encouraging results after repair of posterior lateral meniscus root tears. Whether root repair can prevent the development of osteoarthritis is currently unknown. CONCLUSION: A posterior lateral meniscus root tear is a clinical relevant but most likely underrecognized concomitant injury in patients with a tear of the ACL. This article may support clinicians in diagnosing and treating this unique type of meniscus tear. LEVEL OF EVIDENCE: V.