Direct contact and very rapid valgus distortion characterise the injury mechanism of anterior cruciate ligament ruptures in judo.

PURPOSE: To analyse anterior cruciate ligament (ACL) rupture (ACLR) injury mechanisms in competitive judo using systematic video analysis, focusing on contact situations and biomechanics. METHODS: Seventeen videos of judo competitions wherein athletes developed ACLRs were included and retrospectively evaluated by five analysts. In all videos, the moment of initial contact and the index frame were defined. The judo techniques leading to the injury; the occurrence of direct contact, indirect contact or noncontact mechanisms; the time interval between the initial contact and index frame; the positions of the hip, knee and foot in relation to the initial contact and index frame; and the balance status during the initial contact and index frame were recorded. RESULTS: Eleven (65%) of ACLRs in judo involved direct contact. The mean time interval between initial contact and index frame was 15 ± 22 ms. Thirteen (77%) athletes were not balanced at initial contact. In the index frame, the hip was abducted in all cases and in combination with internal rotation in 12 (71%) cases. From initial contact to index frame, hip flexion increased in all cases; at index frame, the knee joint was internally rotated relative to the trunk in 12 (71%) cases, and the knee flexion angles increased from the initial contact. In the index frame, the foot was externally rotated relative to the knee in 12 (71%) cases, and severe valgus development of the knee with valgus collapse was observed in 14 (82%) cases. CONCLUSIONS: A direct attack on the knee was the most common injury mechanism observed. Valgus distortion appears to be the most important component of the mechanism of injury. With this knowledge, 'modified defence reactions' for specific judo techniques can be developed to reduce the injury risk. LEVEL OF EVIDENCE: Level IV.

Malrotated lateral knee radiographs do not allow for a proper assessment of medial or lateral posterior tibial slope.

PURPOSE: The aim of this study was to investigate whether malrotation of lateral knee radiographs influences posterior tibial slope (PTS) measurements. METHODS: Lateral knee radiographs of all patients who underwent knee surgery at a single institution between June 2022 and January 2023 and received multiple lateral knee radiographs were included. Radiographs were categorised as malrotated lateral knee radiographs or lateral knee radiographs based on the radiographic distance between the medial and lateral posterior femoral condyles. Medial PTS (MPTS) and lateral PTS (LPTS) were evaluated on malrotated lateral knee radiographs and lateral knee radiographs and compared using the paired t test. Intra- and interrater reliability between four raters were assessed for MPTS and LPTS measurements. RESULTS: A total of 92 lateral knee radiographs (46 pairs of malrotated lateral knee radiographs and lateral knee radiographs; 50.0% right side) from 46 patients (33.2 ± 12.4 years, 69.6% male) were included. Mean posterior femoral condyle distance in malrotated lateral knee radiographs was 8.1 ± 4.4 mm. Overall, MPTS and LPTS were significantly higher on malrotated lateral knee radiographs versus lateral knee radiographs (medial: 10.5 ± 3.2° vs. 9.7 ± 3.5°, p < 0.05; lateral: 10.6 ± 3.4° vs. 9.7 ± 3.3°, p < 0.05). Mean absolute difference between MPTS and LPTS on malrotated lateral knee radiographs versus lateral knee radiographs were |1.9| ± |1.5|° and |2.0| ± |1.8|°, respectively. Intrarater reliability was 'moderate' and interrater reliability was 'good' for both MPTS and LPTS. CONCLUSION: Malrotation of lateral knee radiographs led to a significant distortion of both the MPTS and LPTS. In clinical practice, attention should be placed on the (mal)rotation of lateral knee radiographs, especially in patients for whom a slope-correcting osteotomy is being discussed. LEVEL OF EVIDENCE: Level IV.

Management after acute injury of the anterior cruciate ligament (ACL). Part 3: Recommendation on surgical treatment.

PURPOSE: The aim of this consensus project was to give recommendations regarding surgical treatment of the anterior cruciate ligament (ACL) injured patient. METHODS: For this consensus process, an expert, steering and rating group was formed. In an initial online meeting, the steering group, together with the expert group, formed various key topic complexes for which multiple questions were formulated. For each key topic, a structured literature search was performed by the steering group. The results of the literature review were sent to the rating group with the option to give anonymous comments until a final consensus voting was performed. Sufficient consensus was defined as 80% agreement. RESULTS: During this consensus process, 30 topics regarding the surgical management and technique of ACL reconstruction were identified. The literature search for each key question resulted in 30 final statements. Of these 30 final statements, all achieved consensus. CONCLUSIONS: This consensus process has shown that surgical treatment of ACL injury is a complex process. Various surgical factors influence patient outcomes. The proposed treatment algorithm can be used as a decision aid for the surgeon. LEVEL OF EVIDENCE: Level V.

The End of the Formal Rehabilitation Is Not the End of Rehabilitation: Knee Function Deficits Remain After Anterior Cruciate Ligament Reconstruction.

OBJECTIVE: To rate athletes' functional ability and return to sport (RTS) success at the end of their individual, formal, medically prescribed rehabilitation after anterior anterior cruciate ligament (ACL) reconstruction. METHODS: In our prospective multicenter cohort study, 88 (42 females) adults aged 18-35 years after acute unilateral ACL rupture and subsequent hamstring grafting were included. All patients were prospectively monitored during their rehabilitation and RTS process until the end of their formal rehabilitation and RTS release. As outcome measures, functional hop and jump tests (front hop, balance hops, and drop jump screening test) and self-report outcomes (Knee Injury and Osteoarthritis Outcome Score, ACL-RTS after injury) were assessed. Literature-based cut-off values were selected to rate each performance as fulfilled or not. RESULTS: At 7.5 months (SD 2.3 months) after surgery, the percentage of participants meeting the functional thresholds ranged from 4% (Knee Injury and Osteoarthritis Outcome Score SPORT) and over 44% (ACL-RTS after injury sum score) to 59% (Knee Injury and Osteoarthritis Outcome Score activities of all daily living) in the self-report and from 29% (Balance side hop) to 69% (normalized knee separation distance) in performance testing. Only 4% fulfilled all the cut-offs, while 45% returned to the same type and level of sport. Participants who successfully returned to their previous sport (type and level) were more likely to be "over-cut-off-performers." CONCLUSIONS: The low share of the athletes who fulfilled the functional RTS criteria highlights the importance of continuing the rehabilitation measures after the formal completion to assess the need for and success of, inter alia, secondary-preventive therapies.

Favorable rates of return to activity and work following lateral closing wedge distal femoral osteotomy for femoral-based symptomatic varus malalignment: an analysis at a mean 6-year follow-up.

PURPOSE: To evaluate return to sport (RTS), work (RTW) and clinical outcomes following lateral closing wedge distal femoral osteotomy (LCW-DFO) for symptomatic femoral varus malalignment. METHODS: Consecutive patients who underwent LCW-DFO for symptomatic varus malalignment between 12/2007 and 03/2018 were included. The International Knee Documentation Committee (IKDC) Score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Lysholm score, Tegner Activity Scale, and visual analogue scale (VAS) for pain were collected preoperatively and at a minimum of 24 months postoperatively. RTS and RTW were assessed by questionnaire. RESULTS: Thirty-two patients (mean age: 45.9 ± 12.3 years), who underwent LCW-DFO for femoral-based varus malalignment (6.4 ± 3.0°), were included at a mean follow-up of 72.7 ± 39.1 months. The patient collective significantly improved in IKDC (51.8 ± 12.3 to 61.8 ± 21.5, p = 0.010; 95% CI = 3-21), WOMAC (26.7 ± 17.6 to 12.5 ± 13.5; p < 0.001; 95% CI = 21-6) and Lysholm (46.5 ± 19.4 to 67.9 ± 22.8 points (p < 0.01; 95% CI = 9-31)) scores at final follow-up. The VAS for pain reduced significantly postoperatively (4.8 ± 2.3 points to 2.6 ± 2.3 points (p = 0.002; 95% CI = 0-3)). Following LCW-DFO, 96% of patients returned to sports at a mean of 5.3 ± 2.9 months. Yet, a shift to lower impact sports compared to one year preoperatively was observed, with patients participating in a significantly lower number of high-impact disciplines (p = 0.024) and fewer hours in high-impact sports (p = 0.034). Twenty-three out of 24 patients returned to work at a mean 11.4 ± 10.9 weeks, with 18 patients reporting a similar or superior working ability. CONCLUSION: Undergoing isolated LCW-DFO for symptomatic femoral-based varus malalignment enabled the vast majority of patients to RTS and RTW along with a significant functional improvement at mid-term follow-up. However, patients' expectations have to be adequately managed regarding a limited probability to return to high-impact sports and work after surgery. LEVEL OF EVIDENCE: Retrospective case series; Level IV.

Management after acute rupture of the anterior cruciate ligament (ACL). Part 1: ACL reconstruction has a protective effect on secondary meniscus and cartilage lesions.

PURPOSE: The aim of this consensus project was to validate which endogenous and exogenous factors contribute to the development of post-traumatic osteoarthritis and to what extent ACL (anterior cruciate ligament) reconstruction can prevent secondary damage to the knee joint. Based on these findings, an algorithm for the management after ACL rupture should be established. METHODS: The consensus project was initiated by the Ligament Injuries Committee of the German Knee Society (Deutsche Kniegesellschaft, DKG). A modified Delphi process was used to answer scientific questions. This process was based on key topic complexes previously formed during an initial face-to-face meeting of the steering group with the expert group. For each key topic, a comprehensive review of available literature was performed by the steering group. The results of the literature review were sent to the rating group with the option to give anonymous comments until a final consensus voting was performed. Consensus was defined a-priori as eighty percent agreement. RESULTS: Of the 17 final statements, 15 achieved consensus, and 2 have not reached consensus. Results of the consensus were summarized in an algorithm for the management after ACL rupture (infographic/Fig. 2). CONCLUSION: This consensus process has shown that the development of post-traumatic osteoarthritis is a complex multifactorial process. Exogenous (primary and secondary meniscus lesions) and endogenous factors (varus deformity) play a decisive role. Due to the complex interplay of these factors, an ACL reconstruction cannot always halt post-traumatic osteoarthritis of the knee. However, there is evidence that ACL reconstruction can prevent secondary joint damage such as meniscus lesions and that the success of meniscus repair is higher with simultaneous ACL reconstruction. Therefore, we recommend ACL reconstruction in case of a combined injury of the ACL and a meniscus lesion which is suitable for repair. LEVEL OF EVIDENCE: Level V.

Management after acute injury of the anterior cruciate ligament (ACL), part 2: management of the ACL-injured patient.

PURPOSE: The aim of this consensus project was to create a treatment algorithm for the management of the ACL-injured patient which can serve as an aid in a shared decision-making process. METHODS: For this consensus process, a steering and a rating group were formed. In an initial face-to-face meeting, the steering group, together with the expert group, formed various key topic complexes for which various questions were formulated. For each key topic, a structured literature search was performed by the steering group. The results of the literature review were sent to the rating group with the option to give anonymous comments until a final consensus voting was performed. Sufficient consensus was defined as 80% agreement. RESULTS: During this consensus process, 15 key questions were identified. The literature search for each key question resulted in 24 final statements. Of these 24 final statements, all achieved consensus. CONCLUSIONS: This consensus process has shown that ACL rupture is a complex injury, and the outcome depends to a large extent on the frequently concomitant injuries (meniscus and/or cartilage damage). These additional injuries as well as various patient-specific factors should play a role in the treatment decision. The present treatment algorithm represents a decision aid within the framework of a shared decision-making process for the ACL-injured patient. LEVEL OF EVIDENCE: Level V.

Low postoperative complication rate with high survival rate and good clinical outcome 9 years after autologous chondrocyte transplantation of the knee joint.

PURPOSE: To investigate postoperative complications and associated risk factors for failure following autologous chondrocyte transplantation ("ACT") as well as its long-term survival and clinical function. It was hypothesized that ACT is a safe technique for cartilage repair with a low incidence of postoperative complications and rare rates of revision surgery combined with a high long-term survival and good to excellent clinical outcome in long-term-follow-up. METHODS: All patients undergoing ACT-Cs of the knee joint between 2006 and 2012 at the author's institution were included in this retrospective study. Concomitant procedures had been performed if necessary. Early postoperative complications, revision surgeries, failure and risk factors for those events were evaluated 6 months after the surgery. Long-term clinical outcome was assessed using the Lysholm Score, the Tegner Score, a 10-grade scale for satisfaction and the Visual Analogue Scale (VAS) at a minimum follow-up of 9 years postoperatively. Long-term survival was calculated using revision surgeries, clinical failures and conversion procedures to create a Kaplan-Meier analysis. A subgroup analysis for different defect locations was performed. 139 patients were included in this study (27% female/ 73%male; age 26.7 [21.7; 35.2] years). The median defect size was 4.0 [3.0; 6.0] cm2 (40% medial femoral condyle (MFC), 17% lateral femoral condyle (LFC), 36% patella, 19% trochlea). 97 (70%) of the patients had undergone previous surgery and 84 (60%) underwent concomitant procedures. RESULTS: Postoperatively, 8% of patients had complications (4% bleeding, 2% arthrofibrosis, 2% infection), 7% of patients needed revision surgery. 12% of patients had a prolonged deficit in ROM, that did not require revision surgery. No significant difference in terms of complications was found between the patellofemoral and femorotibial group. Patients demonstrated good patient reported long-term outcomes 9-15 years after the index surgery (Tegner: 4.7 ± 1.8; VAS: 2.4 ± 2.1; Lysholm: 80 ± 14; satisfaction with operation: 7.3 ± 1.9). Survival rates were 88% at 9 years, 85% at 11 years, and 85% at 13 years after the index procedure. Reasons for failure included debridement of ACT (n = 4; 5%), revision ACT (n = 3, 3%), conversion to total knee arthroplasty (n = 3, 3%) and conversion to High tibial osteotomy (HTO) (n = 1; 1%)). CONCLUSION: The present study indicates ACT as an effective treatment option for femorotibial- as well as patellofemoral cartilage defects with a high long-term survival and low conversion rate as well as good long-term results regarding knee function and satisfaction. Postoperative complications needing revision surgery are rare. Prolongated deficits of range of motion appear frequently up to six months especially in patellofemoral defects, but can often be successfully addressed by intensified physiotherapy without requiring an arthrolysis. LEVEL OF EVIDENCE: Level III.

Clinical and biomechanical outcomes following patellar tendon repair with suture tape augmentation.

PURPOSE: Patellar tendon ruptures (PTR) occur predominantly in middle-aged patients following indirect trauma. The aim of this study was to quantify the short-term results using a suture tape augmentation technique for the repair of PTR. METHODS: All consecutive patients with acute (< 6 weeks) PTR who underwent suture tape augmentation between 03/2014 and 11/2019 at a single institution with a minimum follow-up of 12 months were retrospectively evaluated. Outcome measures included Visual Analog Scale (VAS) for pain, Tegner Activity Scale (TAS) and return to sport rates, Lysholm score, International Knee Documentation Committee subjective knee form (IKDC) as well as Knee Injury and Osteoarthritis Outcome Score (KOOS). Additionally, a standardized clinical examination and an isometric strength evaluation of knee extension and flexion were performed. It was hypothesized that high return to sport rates and good functional outcome would be observed and that the majority of patients would not present with a severe (> 20%) knee extension strength deficit when compared to the contralateral side. RESULTS: A total of 7 patients (mean age 37.0 ± SD 13.5 years; 6 male/1 female) were available for final assessment at a median follow-up of 17.0 (25-75% IQR 16.0-77.0) months. Three injuries occurred during ball sports, two injuries occurred during winter sports, and one injury each occurred during a motorcycling and skateboarding accident. The average time between trauma and surgery was 4.7 ± 2.6 days. At follow-up, patients reported little pain (VAS: 0 [0-0.4]). Return to sport was possible for all patients 8.9 ± 4.0 months postoperatively at a high level (TAS: 7.0 [6.0-7.0]). Five patients (71.4%) returned to the preinjury level of play, and 2 (28.6%) did not return to the preinjury level of play. Patient-reported outcome measures were moderate to good (Lysholm score: 80.4 ± 14.5; IKDC: 84.2 ± 10.6; KOOS subscales: pain 95.6 ± 6.0, symptoms 81.1 [64.9-89.1], activities of daily living 98.5 [94.1-100], sport and recreation function 82.9 ± 14.1 and knee-related quality of life 75.9 ± 16.3). All patients were very satisfied (57.1%) or satisfied (42.9%) with the postoperative result. No postoperative complications were reported. Strength measurements revealed a severe knee extension deficit in 3 patients (42.9%), but no significant deficit of isometric knee extension or flexion strength in comparison with the contralateral side was observed overall (p > 0.05). CONCLUSION: Suture tape augmentation in acute PTR repair leads to good functional outcome without major complications. Although a severe knee extension strength deficit may occur in some patients postoperatively, an excellent return to sports rate and high patient satisfaction can be expected nonetheless. LEVEL OF EVIDENCE: Retrospective cohort study; III.

Midterm outcome and strength assessment after quadriceps tendon refixation with suture anchors.

PURPOSE: Quadriceps tendon ruptures (QTR) occur predominantly in middle-aged patients through violent eccentric contraction that occurs either when trying to regain balance or during a fall on the hyperflexed knee. The aim of this study was to quantify midterm postoperative results, including strength potential measured via standardized strength tests following acute (< six weeks) quadriceps tendon refixation using suture anchors. METHODS: All consecutive patients with QTR who underwent surgical suture anchor refixation between 2012 and 2019 at a single institution with a minimum follow-up of 12 months were retrospectively evaluated. Outcome measures included Tegner Activity Scale (TAS), Lysholm score, International Knee Documentation Committee subjective knee form (IKDC), Knee injury and Osteoarthritis Outcome Score (KOOS) subscales, return to work rates, and Visual Analog Scale (VAS) for pain. Additionally, a standardized clinical examination and an isometric strength assessment of knee extension and flexion were performed. RESULTS: A total of 17 patients (median age 61.0 [25-75% IQR 50.5-72.5]) were available for final assessment at a mean follow-up of 47.1 ± SD 25.4 months. The majority of patients were male (82.4%) and most injuries occurred due to a fall on the hyperflexed knee (76.5%). The average time interval between trauma and surgery was 12.7 ± 7.5 days. Patients achieved a moderate level of activity postoperatively with a median TAS of 4 (3-5.5) and reported good to excellent outcome scores (Lysholm score: 97 (86.5-100); IKDC: 80.7 ± 13.5; KOOS subscales: pain 97.2 (93.1-100), symptoms 92.9 (82.5-100), activities of daily living 97.1 (93.4-100), sport and recreation function 80 (40-97.5) and knee-related quality of life 87.5 (62.5-100). All patients were able to fully return to work and reported little pain [VAS: 0 (0-0)]. No postoperative complications were reported. Strength measurements revealed a significant deficit of knee extension strength in comparison to the contralateral side (p = 0.011). CONCLUSION: Suture anchor refixation of acute QTR leads to good functional results and high patient satisfaction without major complications. Isometric knee extension strength, however, may not be fully restored compared to the unaffected side.

Editorial Commentary: Double-Sling Transfer of Both the Conjoined Tendons and Long Head Biceps Tendon for Glenoid Bone Loss in Patients With Shoulder Instability Shows Biomechanical Benefit in Shoulder Abduction and External Rotation But May Be Insufficient in Mid-Range Arm Positions.

Recurrence of shoulder glenohumeral instability is exacerbated in cases of glenoid bone loss. Surgical bone transfer techniques well address the issue. Innovative soft-tissue tendon transfers may fill the defect plus provide a sling effect. Double-sling transfer of both the conjoined tendons and long head biceps tendon for glenoid bone loss in patients with shoulder instability shows biomechanical benefit in shoulder abduction and external rotation. However, as the sling effect is less pronounced in mid-range arm position, the benefit of double-sling transfer may be insufficient. Moreover, the biomechanical models are limited relative to the complexity of clinical glenohumeral function, and obviously limited to time-zero analysis. We should be careful before we abandon bony augmentation procedures.

Improved Clinical Outcome and High Rate of Return to Low-Impact Sport and Work After Knee Double Level Osteotomy for Bifocal Varus Malalignment.

PURPOSE: To evaluate return to sport (RTS) and work (RTW), as well as clinical outcomes following double level osteotomy (DLO) via combined medial open wedge high tibial osteotomy and lateral closing wedge distal femoral osteotomy for bifocal symptomatic varus malalignment, and to compare these outcome parameters between patients undergoing a single surgery and those undergoing a two-stage procedure. METHODS: Consecutive patients who underwent DLO for symptomatic varus malalignment between 12/2007 and 03/2018 were enrolled. Patients converted to arthroplasty (n = 3) during follow-up were excluded. Outcome measures included the International Knee Documentation Committee (IKDC) Score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Lysholm score, Tegner Activity Scale, and visual analog scale (VAS) for pain, which were collected preoperatively and at a minimum of 24 months postoperatively. RTS and RTW were evaluated by questionnaire. Outcome measures were compared between DLO performed in a single- versus a two-stage surgery. RESULTS: Thirty-two patients (mean age: 44.2 ± 12.6 years), who underwent DLO for varus malalignment (10.1° ± 2.9°) were included at a mean follow-up of 56.9 ± 35.3 months (range: 24-148). Compared to preoperatively, these patients significantly improved in IKDC (50.4 ± 13.9 to 66.1 ± 15.4; P < .001), WOMAC (29.7 ± 19.2 to 11.8 ± 13.5; P < .001) and Lysholm (53.6 ± 23.6 to 73.1 ± 23.6; P = .002) scores at final follow-up. For the WOMAC score, 78% of the patients included reached the minimally important clinical difference, along with a significant reduction of the VAS for pain (5.0 ± 3.0 to 2.5 ± 2.4; P < .001). Postoperatively, 96% of patients returned to sport after 7.7 ± 4.8 months, but at a lower frequency (P = .010) and to fewer disciplines (P = .005) with a shift to low-impact sports. 90% of the patients returned to work at a mean 5.9 ± 9.4 months, with 79% reporting a similar or superior working ability. Patients undergoing a two-stage procedure recovered to full physical working ability at a significantly longer duration, as compared to a single-stage procedure (9.8 ± 3.8 vs 9.0 ± 13.1 months; P = .047). CONCLUSION: The majority of patients undergoing DLO for symptomatic varus malalignment, who were not converted to arthroplasty, experienced clinically significant functional improvement at mid-term follow-up. Return to sport and work rates in these patients were high; however, a shift to lower-impact sports disciplines was observed. Similar clinical outcomes can be expected when performing DLO in a single surgery or a two-stage procedure. LEVEL OF EVIDENCE: Retrospective case series; Level IV.

Biologically Augmented Suture for Ligament Bracing Procedures Positively Affects Human Ligamentocytes and Osteoblasts In Vitro.

PURPOSE: The purpose was to evaluate the response of human ligamentocytes and osteoblasts after biological augmentation with thrombin, concentrated bone marrow aspirate (cBMA), or platelet-rich plasma (PRP) on two different types of nonresorbable flat braided suture used for ligament bracing. METHODS: Uncoated (U) and collagen-coated (C) flat braided suture material was augmented with either thrombin (T), cBMA (B), PRP (P), or a combination of these three (A), while platelet-poor plasma was used as a source for fibrin (F) in each assay. Previously cultured ligamentocytes and osteoblasts were added with a defined density and assayed after the required time period for adhesion, proliferation, and alkaline phosphatase activity. RESULTS: Biological augmentation of uncoated [(UFT, UFBT, UFA; P < .001), (UFPT; P = .017)] and collagen-coated suture (CFT, CFPT, CFBT, CFA; P < .001) led to a significantly higher ligamentocyte adhesion. Significantly higher adhesion was also observed for osteoblasts (UFT, UFPT, UFBT, UFA; P < .001; CFT, CFPT, CFBT, CFA; P < .001). Similarly, ligamentocyte proliferation was significantly higher [(UFT, UFPT, UFA; P = .009), (UFBT; P = .001), (CFT; P = .009), (CFBT; P = .001), and (CFA; P = .01)]. Osteoblasts showed significantly higher proliferation as well [(UFT, UFPT, UFA; P = .002), (UFBT; P = .001); (CFT: P = .003), and (CFPT, CFBT, CFA; P = .001)]. Augmentation with thrombin, PRP, and BMA for uncoated (UFT; P = .006, UFPT; P = .035, UFBT; P = .001) and BMA for coated suture (CFBT; P = .027) led to significantly higher alkaline phosphatase activity. CONCLUSION: Biological enhancement of suture used for ligament bracing significantly increased ligamentocyte and osteoblast adhesion and proliferation, as well as alkaline phosphatase activity of osteoblasts in an in vitro model. After biological augmentation, cellular adhesion, proliferation, and alkaline phosphatase activity changed up to 1,077%, 190%, and 78%, respectively. Furthermore, no overall superiority between uncoated or collagen-coated suture material was observed for cellular adhesion, proliferation, or alkaline phosphatase activity. CLINICAL RELEVANCE: This study provides in vitro data on a new treatment concept of biologic augmentation for acute ligamentous lesions treated with ligament bracing that has not been widely described. This concept may improve the healing of injured ligaments, in addition to providing immediate biomechanical stabilization.

Good clinical outcomes after patellar cartilage repair with no evidence for inferior results in complex cases with the need for additional patellofemoral realignment procedures: a systematic review.

PURPOSE: Focal, patellar cartilage defects are a challenging problem as most cases have an underlying multifactorial pathogenesis. This systematic review of current literature analysed clinical results after regenerative cartilage repair of the patella with a special focus on the assessment and treatment of existing patellofemoral malalignment. METHODS: A systematic review was conducted to identify articles reporting clinical results after cartilage regenerative surgeries of the patella using the PubMed and Scopus database. The extracted data included patient-reported outcome measures (PROMS) and whether cartilage repair was performed alone or in combination with concomitant surgeries of underlying patellofemoral co-pathologies. In cases of isolated cartilage repair, specific exclusion criteria regarding underlying co-pathologies were screened. In cases of concomitant surgeries, the type of surgeries and their specific indications were extracted. RESULTS: A total of 35 original articles were included out of which 27 (77%) were cohort studies with level IV evidence. The most frequently used technique for cartilage restoration of the patella was autologous chondrocyte implantation (ACI). Results after isolated cartilage repair alone were reported by 15 (43%) studies. Of those studies, 9 (60%) excluded patients with underlying patellofemoral malalignment a priori and 6 (40%) did not analyse underlying co-pathologies at all. Among the studies including combined surgeries, the most frequently reported concomitant procedures were release of the lateral retinaculum, reconstruction of the medial patellofemoral ligament (MPFL), and osteotomy of the tibial tubercle. In summary, these studies showed lower preoperative PROMS but similar final PROMS in comparison with the studies reporting on isolated cartilage repair. The most frequently used PROMS were the IKDC-, Lysholm- and the Modified Cincinnati Score. CONCLUSION: This comprehensive literature review demonstrated good clinical outcomes after patellar cartilage repair with no evidence of minor results even in complex cases with the need for additional patellofemoral realignment procedures. However, a meaningful statistical comparison between isolated patellar cartilage repair and combined co-procedures is not possible due to very heterogeneous patient cohorts and a lack of analysis of specific subgroups in recent literature. LEVEL OF EVIDENCE: Level IV.

Excellent clinical and radiological outcomes after both open flake refixation and autologous chondrocyte implantation following acute patella dislocation and concomitant flake fractures.

PURPOSE: To investigate clinical and magnetic resonance (MR) imaging results of patients undergoing patella stabilization with either open flake refixation (oFR) or autologous chondrocyte implantation (ACI) and concomitant soft tissue patella stabilization after sustaining primary, acute patella dislocation with confirmed chondral and/or osteochondral flake fractures. It was hypothesized that refixation will lead to better results than ACI at mid-term follow-up. METHODS: A retrospective chart review was conducted to identify all patients undergoing oFR or ACI after sustaining (osteo-)chondral flake fractures and concomitant soft tissue patella stabilization following primary, acute patella dislocation between 01/2012 and 09/2018 at the author's institution. Patients were excluded if they were aged < 14 years or > 30 and had previous knee surgeries at the index knee. Clinical outcomes were assessed using the Tegner activity score, Kujala score, subjective IKDC score, and the KOOS score at a minimum follow-up of 24 months postoperatively. MR images were assessed using the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) 2.0 knee score. Thirty patients were included in the study, with 16 patients assorted to the oFR group and 14 patients to the ACI group (Follow-up 81%). RESULTS: Demographic data did not show significant group differences (oFR: 6 females, 10 males; age 26.9 ± 5.6 years, FU: 57 months (27-97 months); ACI: 9 females, 5 males; age 25.5 ± 4.9 years, FU: 51 months (29-91 months); n.s.). Defect location was similar in both groups (oFR: 12 × patella/4 × lateral femoral condyle; ACI: 12/2; n.s.). Both groups showed excellent clinical outcomes, with no statistically significant difference between both the groups (oFR group vs. ACI group: Tegner: 5.1 ± 1.8 vs. 5.1 ± 1.4; Kujala: 86.1 ± 12.6 vs. 84.9 ± 9.1; IKDC: 83.8 ± 15.0 vs. 83.6 ± 11.3; KOOS: 83.3 ± 14.0 vs. 83.6 ± 12.0; n.s.). One patient in each group suffered a patella re-dislocation and needed revision surgery. The MOCART 2.0 score showed good results for the oFR group (68.2 ± 11.1) and the ACI group (61.1 ± 16.9) while no significant differences were noted between both the groups. The inter-rater reliability was excellent (0.847). CONCLUSION: Open refixation of (osteo-)chondral fragments in patients after sustaining acute patella dislocation with (osteo)-chondral flake fractures led to good clinical and radiological results at a minimum follow of 24 months, showing that it is a good surgical option in the treatment algorithm. However, if open refixation is not possible, ACI may be an excellent fallback option in these younger patients with equally good clinical and radiological outcomes, but requiring a second minimally invasive surgery. LEVEL OF EVIDENCE: III.

Autologous chondrocyte implantation combined with anterior cruciate ligament reconstruction: similar short-term results in comparison with isolated cartilage repair in ligament intact joints.

PURPOSE: Both acute ruptures of the anterior cruciate ligament (ACL) as well as chronic ACL insufficiency show a high association with focal cartilage defects of the knee. However, the results after combined ACL reconstruction and cartilage repair are not well investigated. The aim of the present study was to investigate the short-term outcomes after autologous chondrocyte implantation (ACI) in combination with ACL reconstruction and to compare the results with patients who underwent isolated ACI in ligament intact knees. METHODS: All patients who were registered in the German Cartilage Registry with ACI for focal cartilage defects in the knee joint in combination with ACL reconstruction and who completed the 24 month follow-up were included in the study group. A matched-pair procedure according to gender, defect location, defect size, and age was used to create a control group of patients with isolated ACI in ACL intact joints. The Knee Injury and Osteoarthritis Outcome Score (KOOS) and the numeric analog scale for pain (NAS) were used to assess the preoperative state as well as the clinical outcomes 12 and 24 months after surgery. RESULTS: A total of 34 patients were included in both the study group (age mean 33.3 ± SD 8.8 years) and the control group (33.6 ± 8.4 years) with a median defect size of 466 (25%-75% IQR 375-600) mm2 and 425 (IQR 375-600) mm2, respectively. In comparison with the preoperative state (median 67, IQR 52-75), the study group showed a significant increase of the total KOOS after 12 months (78, IQR 70-86; p = 0.014) and after 24 months (81, IQR 70-84; p = 0.001). The NAS for pain did not change significantly in the postoperative course. In comparison with the control group there was no significant difference for the total KOOS neither preoperative (control group median 67, IQR 52-73) nor at any postoperative time point (12 months: 82, IQR 67-93; 24 months: 81, IQR 71-91). CONCLUSION: The clinical short-term outcomes after ACI at the knee joint in combination with ACL reconstruction are good and similar to the results after isolated ACI in ligament intact knees. LEVEL OF EVIDENCE: III.

Rotational range of motion of elliptical and spherical heads in shoulder arthroplasty: a dynamic biomechanical evaluation.

INTRODUCTION: Elliptical shape humeral head prostheses have been proposed to reflect a more anatomic shoulder replacement. Its effect on the rotational range of motion (ROM) compared to a standard spherical head is still not understood. The purpose was to investigate if there would be a difference in rotational ROM when comparing elliptical and spherical prosthetic heads in a dynamic shoulder model. The authors hypothesized that the use of elliptical heads would result in significantly more rotational ROM compared to the spherical head design. MATERIALS AND METHODS: Six fresh-frozen, cadaveric shoulders were evaluated using a dynamic shoulder model. After being tested in the native condition, each specimen underwent 6 conditions in the hemiarthroplasty state: (1) matched-fit spherical head, (2) oversized spherical head, (3) undersized spherical head, (4) matched-fit elliptical head, (5) oversized elliptical head, and (6) undersized elliptical head. Following conversion to total shoulder arthroplasty (TSA), the 6 prior conditions were rerun. Each condition was tested at 0°, 30° and 60° of glenohumeral abduction. Rotational ROM was quantified using 3-dimensional tracking, while dynamically applying alternating forces for internal and external rotation via the rotator cuff tendons. RESULTS: Elliptical and spherical prosthetic heads showed no significant difference in the degree of the total, internal, and external rotational ROM for both the hemiarthroplasty and TSA state. Conversion from hemiarthroplasty to TSA resulted in less degree of total rotational ROM for both head designs in all abduction positions, without reaching statistical significance. There was a significant decrease in total, internal, and external rotational ROM for both elliptical and spherical heads in every replacement condition, when comparing 0° to 30° and 60° of abduction (P < 0.05, respectively). CONCLUSION: In a dynamic shoulder model, elliptical and spherical prosthetic head designs showed no significant difference in the degree of the total, internal, and external rotational ROM in both the hemiarthroplasty and TSA state. LEVEL OF EVIDENCE: Controlled laboratory study.

Midterm outcome and strength assessment after proximal rectus femoris refixation in athletes.

PURPOSE: Proximal rectus femoris avulsions (PRFA) are relatively rare injuries that occur predominantly among young soccer players. The aim of this study was to evaluate midterm postoperative results including strength potential via standardized strength measurements after proximal rectus femoris tendon refixation. It was hypothesized that the majority of competitive athletes return to competition (RTC) after refixation of the rectus femoris tendon without significant strength or functional deficits compared to the contralateral side. METHODS: Patients with an acute (< 6 weeks) PRFA who underwent surgical refixation between 2012 and 2019 with a minimum follow-up of 12 months were evaluated. The outcome measures compiled were the median Tegner Activity Scale (TAS) and mean RTC time frames, Harris Hip Score (HHS), Hip and Groin Outcome Score (HAGOS) subscales, International Hip Outcome Tool-33 (iHOT-33), and Visual Analog Scale (VAS) for pain. In addition, a standardized isometric strength assessment of knee flexion, knee extension, and hip flexion was performed to evaluate the functional result of the injured limb in comparison to the uninjured side. RESULTS: Out of 20 patients, 16 (80%) patients were available for final assessment at a mean follow-up of 44.8 ± SD 28.9 months. All patients were male with 87.5% sustaining injuries while playing soccer. The average time interval between trauma and surgery was 18.4 ± 8.5 days. RTC was possible for 14 out of 15 previously competitive athletes (93.3%) at a mean 10.5 ± 3.4 months after trauma. Patients achieved a high level of activity postoperatively with a median (interquartile range) TAS of 9 (7-9) and reported good to excellent outcome scores (HHS: 100 (96-100); HAGOS: symptoms 94.6 (89.3-100), pain 97.5 (92.5-100), function in daily living 100 (95-100), function in sport and recreation 98.4 (87.5-100), participation in physical activities 100 (87.5-100), quality of life 83.1 ± 15.6; iHot-33: 95.1 (81.6-99.8)). No postoperative complications were reported. Range of motion, isometric knee flexion and extension, as well as hip flexion strength levels were not statistically different between the affected and contralateral legs. The majority of patients were "very satisfied" (56.3%) or "satisfied" (37.5%) with the postoperative result and reported little pain (VAS 0 (0-0.5)). CONCLUSION: Surgical treatment of acute PRFA yields excellent postoperative results in a young and highly active cohort. Hip flexion and knee extension strength was restored fully without major surgical complications. LEVEL OF EVIDENCE: Retrospective cohort study; III.

A novel mouse model to evaluate neuropeptide Y-mediated melanocyte pathology.

Vitiligo is an autoimmune disease characterized by depigmented patches of skin due to loss of the pigment-producing melanocytes. No cure exists for vitiligo. The available treatments are inefficient for many patients, suggesting that universal treatment approaches may be inappropriate. Deeper understanding of the mechanistic basis for variability in vitiligo aetiologies is necessary. Genetic mutations in neuropeptide Y (NPY), a widely distributed protein, are associated with increased NPY expression and increased susceptibility for vitiligo. NPY is also upregulated in the circulation and lesional skin of some vitiligo patients. However, the contributions of NPY to melanocyte pathology are not understood, and presently there are no models with which to investigate this possibility. In this study, we employed NPY-overexpressing mice to explore the role of NPY in melanocyte dysfunction. Our results show that NPY overexpression induces progressive hair greying (depigmentation) due to premature depletion of follicular melanocyte stem cells. Additionally, NPY transcripts and protein are elevated in the skin and melanocytes of these mice, respectively, suggesting that these effects may be mediated locally. Together, these results suggest that supraphysiological levels of NPY in the skin can induce melanocyte dysfunction, thus identifying this mouse line as a novel model to study NPY-mediated melanocyte pathology.

Nucleated Cell Count Has Negligible Predictive Value for the Number of Colony-Forming Units for Connective Tissue Progenitor Cells (Stem Cells) in Bone Marrow Aspirate Harvested From the Proximal Humerus During Arthroscopic Rotator Cuff Repair.

PURPOSE: To evaluate whether nucleated cell count (NCC) could serve as an approximation for the number of colony-forming units (CFUs) in concentrated bone marrow aspirate (cBMA) obtained from the proximal humerus. METHODS: Bone marrow aspirate (BMA) was harvested from the proximal humerus in 96 patients (mean age 56.2 ± 7.0 years) during arthroscopic rotator cuff repair. Following concentration of the aspirate, nucleated cells of each sample were counted. The total number of CFUs was evaluated under the microscope at their first appearance, usually after 5 to 10 days in culture. Fluorescence-activated cell sorting analysis and assays for osteogenic, adipogenic, and chondrogenic differentiation were performed. Linear regression was assessed to predict the number of CFUs by using NCC. Age, sex, and body mass index (BMI) were evaluated as independent variables. RESULTS: The average volume of the obtained BMA was 86.7 ± 35.2 mL. The cBMA contained a mean of 26.3 ± 6.8 × 106 nucleated cells per mL, which yielded a mean of 1421.7 ± 802.7 CFUs in cell culture. There were no significant differences in NCC or number of CFUs when sex, volume of BMA, age, or BMI was examined independently (P >.05, respectively). Linear regression found that NCC was of limited predictive value for the total number of CFUs being yielded after cell culture (r2 = 0.28 with a root mean square error of 679.4). CONCLUSION: NCC was of negligible predictive value for the total number of CFUs for connective tissue progenitor cells in BMA harvested from the proximal humerus during arthroscopic rotator cuff repair. CLINICAL RELEVANCE: NCC is often used to assess the quality of cBMA samples for biological augmentation during surgery. The limited predictive value of this measurement tool is of clinical importance, because effectiveness of BMA applications has been suggested to depend on the concentration of progenitor cells within the sample.