Single-Bundle Versus Double-Bundle Anterior Cruciate Ligament Reconstruction-5-Year Results.

PURPOSE: To compare anatomic single-bundle (SB) with double-bundle (DB) anterior cruciate ligament reconstruction (ACL-R) and to evaluate the respective clinical outcome results. METHODS: In a prospective randomized study, 64 patients were included and separated into 2 groups. Anatomic SB and DB ACL-Rs were performed with hamstring tendons. Five years after surgery, the follow-up (FU) examination comprised International Knee Documentation Committee (IKDC) 2000, Laxitester (ORTEMA Sport Protection, Markgroeningen, Germany) measurement, and radiograph evaluation. Power calculation was performed to achieve a 95% confidence interval and 80% power on the base of 7-point IKDC subjective difference between the groups. RESULTS: A total of 53 patients (83% FU) were examined at 63.2 ± 4.7 months after surgery: 28 patients in the DB group and 25 patients in the SB group. IKDC subjective (SB: 92.8 ± 6.2, DB: 91.6 ± 7.1; P = .55) and objective scores (grade A SB/DB 20%/25%, B SB/DB 72%/57%, C SB/DB 8%/18%, D SB/DB 4%/0%; P = .45) showed no differences comparing both groups. The Laxitester measurements showed no significant difference in regard to anterior-posterior translation in neutral, internal, and external rotation or to rotation angles (P = .79). No difference was seen between the groups regarding osteoarthritic changes and tunnel widening. CONCLUSIONS: At the 5-year FU, no advantage for either the DB or SB technique in ACL-R can be seen with regard to patient-related and objective outcome measures. LEVEL OF EVIDENCE: Level I, prospective randomized controlled clinical trial.

Significant increase of pathogen detection rate by dry arthroscopic biopsies at suspected low-grade infection following total knee arthroplasty: a prospective observational study.

INTRODUCTION: The differentiation between stiff-knee and low-grade periprosthetic joint infection (PJI) is the current diagnostic challenge in total knee (TKA) revision arthroplasty. The aim of this study was to investigate the additional value of dry biopsies, compared to wet biopsies, in patients presenting with knee stiffness following primary TKA. MATERIALS AND METHODS: Single center, prospective observational study. Consecutive patients with joint stiffness of unknown origin following primary TKA were enrolled. Patient assessment followed the diagnostic standard algorithm. During diagnostic arthroscopy, synovial fluid (synovial WBC, PMN%) and five dry biopsies (dry) were collected. Then fluid was infused and another five microbiology (wet) and five histological biopsies gathered, all from identical locations. The primary outcome parameter was the difference between the pathogens in wet and dry biopsies. RESULTS: 71 patients (61% females, 67 ± 10 years) were eligible. Preoperative blood serology mean CRP (0.7 ± 1.5 mg/dl; p = 0.852), WBC (6.6 ± 1.7 G/l; p = 0.056), and synovial fluid mean WBC (1639 ± 2111; p = 0.602), PMN% (38 ± 28; p = 0.738) did not differ between patients with negative, positive wet or dry biopsies. The histology was in 11% positive (p = 0.058). In 32% at least one pathogen was detected, 48% from wet, 44% from dry biopsies. An inhomogeneous distribution was found. Cutibacterium acnes (100%) was solely found in wet, Micrococcus luteus (75%), Staphylococcus capitis (67%), and Micrococcus lylae (100%) were predominantly found in dry biopsies. Additional dry biopsies increased the pathogen detection rate by 49%. CONCLUSION: The addition of dry biopsies to the current standard diagnostic algorithm for PJI increased the pathogen detection rate by 49%.

Long-term Results of Arthroscopic Arthrolysis for Arthrofibrosis After Anterior Cruciate Ligament Reconstruction.

PURPOSE: The current study was conducted to evaluate the long-term clinical and radiological outcomes after arthroscopic arthrolysis for arthrofibrosis after anterior cruciate ligament reconstruction (ACLR). METHODS: All patients treated with arthrolysis between 1990 and 1998 were included. Indication was arthrofibrosis in at least one knee compartment or a cyclops syndrome limiting range of motion (ROM) by > 5° of extension deficit and 15° of flexion deficit. International Knee Documentation Committee (IKDC) 2000 subjective and objective, Lysholm score, and x-ray evaluation were documented. Statistical analysis and power calculation were performed (P < .05). RESULTS: One hundred forty-one patients (follow-up, 71%) were examined at a mean of 18.7 ± 2.6 years after arthroscopic arthrolysis. Mean IKDC 2000 score was 79.49 ± 14.32. IKDC objective was normal in 0%, nearly normal in 6%, abnormal in 56%, and severely abnormal in 38%. One hundred percent of patients showed more than grade II osteoarthritis. ROM improvement after arthrolysis did not change significantly compared with midterm results (t = 4.5 years). Patients with persisting motion deficits (P = .02) and after medial meniscus resection (P < .001) at time of ACLR showed significantly greater progression of osteoarthritis in comparison with patients without these additional disorders. In case of arthrolysis later than 1 year after ACLR, a more severe osteoarthritis grade (4% vs 20% grade III; P = .038) and a lower jump distance (IKDC: 61% A, 25% B vs 39% A, 41% B; P = .028) were obvious compared with patients who underwent arthrolysis within the first year after ACLR. CONCLUSIONS: Long-term motion improvement can be achieved by arthrolysis. Persistent loss of motion resulted in a higher degree of osteoarthritis in the study population. Early intervention seems advisable as patients with arthrolysis later than 1 year after index surgery reached worse IKDC objective grading. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Sustained release of rhBMP-2 from microporous tricalciumphosphate using hydrogels as a carrier.

BACKGROUND: Tissue engineering and bone substitutes are subjects of intensive ongoing research. If the healing of bone fractures is delayed, osteoinductive materials that induce mesenchymal stem cells (MSCs) to form bone are necessary. The use of Bone Morphogenetic Protein - 2 is a common means to enhance effectiveness and accelerate the healing process. A delivery system that maintains and releases BMP biological activity in controlled fashion at the surgical site while preventing systemic diffusion (and thereby the risk of undesirable effects by controlling the amount of protein implanted) is essential. In this study, we aimed to test a cylindrical TCP-scaffold (porosity ~ 40 %, mean pore size 5 µm, high interconnectivity) in comparison to BMP-2. Recombinant human BMP-2 was dissolved in different hydrogels as a carrier, namely gelatin and alginate cross-linked with CaCl2-solution, or a solution of GDL and CaCO3. FITC-labeled Protein A was used as a model substance for rhBMP-2 in the pre-trials. For loading, the samples were put in a flow chamber and sealed with silicone rings. Using a directional vacuum, the samples were loaded with the alginate-BMP-2-mixture and the loading success monitored by observing changes in a fluorescent dye (FITC labeled Protein A) under a fluorescence microscope. A fluorescence reader and ELISA were employed to measure the release. Efficacy was determined in cell culture experiments (MG63 cells) via Live-Dead-Assay, FACS, WST-1-Assay, pNPP alkaline phosphatase assay and confocal microscopy. For statistical analysis, we calculated the mean and standard deviation and carried out an analysis of variance. RESULTS: Directional vacuum makes it possible to load nearly 100 % of the interconnected micropores with alginate mixed with rhBMP-2. Using alginate hardened with CaCl2 as a carrier, BMP-2's release can be decelerated significantly longer than with other hydrogels - eg, for over 28 days. The effects on osteoblast-like cells were an increase of the growth rate and expression of alkaline phosphatase while triggering no toxic effect. CONCLUSION: The rhBMP-2-loaded microporous TCP scaffolds possess proliferative and osteoinductive potential. Alginate helps to lower the local growth factor dose below the cytotoxic limit, and allows the release period to be lengthened by at least 28 days.

Single-Bundle Versus Double-Bundle Anterior Cruciate Ligament Reconstruction: A Comparative 2-Year Follow-up.

PURPOSE: To compare anatomic single-bundle (SB) versus double-bundle (DB) anterior cruciate ligament (ACL) reconstruction and to determine possible differences in clinical outcomes. METHODS: In this prospective randomized study, 64 patients were divided into 2 equal groups. Anatomic SB and DB ACL reconstructions were performed using hamstring tendons. A follow-up examination 2 years after surgery comprised International Knee Documentation Committee (IKDC) 2000 assessment, Laxitester (ORTEMA Sport Protection, Markgröningen, Germany) measurement of anteroposterior translation regarding rotational stability, and radiographic evaluation. Statistical analysis and power calculation were performed (P < .05). RESULTS: We examined 62 patients at a mean of 26 months (range, 23.3 to 32.7 months) after surgery. IKDC subjective and objective scores showed no significant differences when both groups were compared. The Laxitester measurements showed no significant differences regarding anteroposterior translation in the neutral position, internal rotation, and external rotation. However, there was a significant improvement in rotational laxity in external rotation in the DB group (P = .02). No differences were seen between the groups regarding osteoarthritic changes and tunnel widening. CONCLUSIONS: There were no differences in IKDC subjective and objective scores between patients who underwent anatomic SB ACL reconstruction and those who underwent anatomic DB ACL reconstruction. LEVEL OF EVIDENCE: Level I, prospective, randomized controlled clinical trial.

Sports activity following total knee arthroplasty in patients older than 60 years.

In a retrospective study with a population over 65 years, sports activity was conducted 6 years after cruciate retaining (CR) total condylar knee arthroplasty (TKA) with rotating platform (RP). Eighty-one Patients (71.8±5.4years) were examined at follow-up 6.4±0.9 years postoperative. Sport was practiced 5.3 hours every week in mean. Patients were active in sports 3.5times per week. Twenty-five percent performed high impact sports, 47% medium impact sports and 52% low impact sports at follow-up. In KOOS sports 60±28 was reached, in WOMAC 12.1±15.1. It can be concluded that in this population 50% of patients were active in medium and low impact sport 6 years after surgery. However, a quarter of patients were also active in high impact sports.

Brace or no-brace after ACL graft? Four-year results of a prospective clinical trial.

PURPOSE: A controversial discussion is held on using stabilizing knee braces after anterior cruciate ligament (ACL) surgery. The current study investigated the influence of a stabilizing knee brace on results after ACL reconstruction using patellar tendon autografts. METHODS: A prospective randomized study was started including 64 patients divided into two equal groups and treated with or without a stabilizing knee brace for 6 weeks post-operatively. A follow-up examination 4 years after operation comprised IKDC 2000, KT1000 measurement, a visual analogue pain scale (VAS; scores 0-10) and radiographic evaluation. The t test for independent and paired samples and the Pearson's Chi-square test were used for statistical analysis (p < 0.05). The primary endpoint was the difference in IKDC classification. RESULTS: Eighty-one per cent of the patients were examined 4 years post-operatively. IKDC 2000 subjective (brace group 90.5 ± 8.9, braceless group 93.2 ± 6.1) and objective results (brace A 30%, B 56%, C 16%; braceless A 32%, B 48%, C 20%) and instrumental measurement of anteroposterior laxity with KT1000 (brace 0.6 ± 2.4 mm, braceless 1.8 ± 3.4 mm) showed no significant differences. VAS pain results were significantly better in the braceless group at 1.0 ± 1.2 versus 1.9 ± 1.4 under sports activity or heavy physical work (p = 0.015). There were no radiographic differences concerning osteoarthritic findings and tunnel widening between the groups. CONCLUSION: Post-operative treatment with a stabilizing knee brace after ACL replacement showed no advantage over treatment without a brace at 4-year follow-up. The use of a knee-stabilizing brace after isolated ACL reconstruction with autologous patellar tendon graft is not recommended. LEVEL OF EVIDENCE: II.

Rotational laxity and collateral ligament laxity following total knee arthroplasty with rotating platform.

PURPOSE: The aim of this study was to evaluate laxity in knees with pre-operative (preop) valgus alignment compared to knees with pre-operative varus alignment after total knee arthroplasty (TKA). METHODS: This was a retrospective study including 81 patients, with six years follow-up, for pre-operative valgus- or varus alignment of the leg. All patients had been supplied with the same cruciate retaining (CR) TKA with rotating platform. Clinical findings were assessed by KSS, OKS and IKDC 2000 score. Rotational knee laxity was evaluated by a validated instrument (Laxitester®) with 2 Nm torque in 30° flexion. Collateral ligament laxity was tested manually in 30° flexion with a bending moment of approximately 5 Nm. Biomechanical results were compared to the contralateral side. RESULTS: Thirty-one patients had a preop valgus alignment of 8.96° and 50 patients a varus leg axis of 4.99° in the mean. In the preop valgus knees rotational analysis showed an increased laxity of 10.7° compared to preop varus knees (p = 0.001). There was no significant difference in medial (valgus 2.6 mm, varus 2.5 mm) and lateral (valgus 2.8 mm, varus 2.7 mm) laxity. KSS and OKS showed no significant differences in the follow-up results. In the IKDC 2000 objective score 50 % of the preop varus knees and 25.8 % of the preop valgus knees were classified as nearly normal. The difference in the IKDC objective was highly significant (p < 0.001). CONCLUSION: Preop valgus knees show a significantly increased rotational laxity but no increased collateral ligament laxity compared to pre-operative varus knees six years after TKA with rotating platform. There is a significant difference in IKDC objective.

Novel endoscopic sacroiliac screw removal technique: reduction of intraoperative radiation exposure.

OBJECTIVE: We report in the following on our technique of endoscopic sacroiliacal screw removal as a new extra-articular endoscopic method in soft tissue surgery, aimed at the reduction of radiation exposure for both the patient and the surgical teams. Patients who underwent endoscopic implant removal from the dorsal pelvic ring (Group A) were retrospectively compared with a control group, in which the screws were removed via the conventional approach (Group B). The parameters of interest were the extent of x-ray exposure in seconds and surgical duration in minutes as well as approach related peri- and postoperative complications. RESULTS: 34 screws were removed endoscopically from 28 patients in group A and 35 screws from 29 patients in group B. The mean skin-to-skin time in group A was 36.1 (15-111) min and 32.7 (12-114) min in group B. The difference was not statistically significant (p > 0.05). The average radiation time in group A was 5.7 ± 3.2 s (range, 0-101 s), while in group B the radiation time was significantly longer (52.6 ± 23 s (range, 0-239 s); p = 0.005). CONCLUSIONS: Endoscopic screw removal from the posterior pelvic ring reduces the intraoperative radiation time whereas the skin-to-skin times do not differ from the conventional procedure. LEVEL OF EVIDENCE: Case-control study, Level III.

Rotator cuff preservation in arthroscopic treatment of calcific tendinitis.

PURPOSE: We sought to evaluate (1) clinical and radiologic results after arthroscopic calcific deposit (CD) removal and (2) the relevance of remnant calcifications (RCs). METHODS: The study included 102 patients undergoing arthroscopic CD removal, preserving integrity of the rotator cuff. Postoperatively, we divided patients into 2 groups according to the extent of CD removal achieved. Group 1 consisted of patients with complete CD removal. Group 2 included patients showing minor RCs. Ninety-three patients (99 shoulders) completed follow-up. The mean patient age was 50.6 years (31 to 68 years), and the mean follow-up period was 37.3 months (24 to 83 months). We obtained anteroposterior (AP) and outlet radiographs before surgery, postoperatively, and at follow-up. We used the absolute and age- and sex-related Constant scores (CSabs, CSrel) as outcome measures. We compared both groups statistically (Mann-Whitney U test; P < .05). RESULTS: Complete CD removal was achieved in 82 of 99 (82.8%) shoulders (group 1). Postoperatively, minor RCs were found in 17 of 99 (17.2%) shoulders (group 2), an average of 58.6% (± 26.2) of the mean preoperative size. All RCs showed complete (14 of 17) or virtually complete (3 of 17) resolution at follow-up. Overall mean CSabs and CSrel were 88.8 points (± 10.4) and 99.0% (± 3.7), respectively. Mean values of CSabs and CSrel in group 1 (89.5 points ± 9.5 and 99.1% ± 3.7, respectively) and group 2 (86.1 points ± 12.9 and 98.7% ± 4.2, respectively) did not differ. CONCLUSIONS: Arthroscopic CD removal, preserving integrity of the rotator cuff yielded good to excellent results in 90% of patients and avoided iatrogenic tendon defects in all patients. Minor RCs did not impair clinical outcome and spontaneously resolved at follow-up. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Indications for and results of arthroscopy in the arthritic knee: a European survey.

PURPOSE: The place of arthroscopic treatment in osteoarthritis of the knee has generated much controversy. A survey was initiated to collect the opinion of experienced surgeons. METHODS: Of the 211 surgeons interviewed, 170 (80.6%) replied to the electronic questionnaire. Respondents had at least ten years of experience in arthroscopy and currently perform more than 100 arthroscopies per year. Various indications and treatment modalities for arthroscopy in osteoarthritis of the knee had to be evaluated on a scale from "excellent" to "no indication". RESULTS: The respondents generally believe that an improvement is more likely in low-grade osteoarthritis (p < 0.001) and in neutral leg axis (p < 0.001). The outcome was rated better if symptoms had persisted for less than six months (p < 0.001) and for patients that were younger than 60 years (p < 0.001). Partial meniscectomy and notchplasty in cases of extension deficit were considered as successful treatment options. Debridement was an accepted indication, with an outcome mainly rated as fair. A majority saw no indication for joint lavage, arthroscopic treatment of arthrofibrosis and removal of osteophytes. The outcome appears to be poor if a bone edema is diagnosed on magnetic resonance imaging prior to arthroscopy. Only 55.9% of respondents were comfortable with the current definition of osteoarthritis. CONCLUSIONS: Experienced arthroscopic surgeons all over Europe believe arthroscopy in osteoarthritis is appropriate, under certain conditions. The major task for surgeons is to select the right patients who are likely to benefit from this intervention.

Suture anchors or transglenoidal sutures for arthroscopic repair of isolated SLAP-2 lesions? A matched-pair comparison of functional outcome and return to sports.

PURPOSE: Presumably, the technique of SLAP refixation has significant influence on outcome. This study analyzes and compares functional outcome and return to sports after arthroscopic suture anchor (SA) and arthroscopic transglenoidal suture (TS) repair of isolated SLAP-2 lesions. METHODS: Twenty-four competitive amateur athletes constituted the two treatment groups of this retrospective matched-pair analysis. In the SA group (n = 12), the mean age was 39.1 years (±12.0) and the mean follow-up period was 4.0 years (±0.6). In the TS group (n = 12), the mean age was 33.8 years (±12.0) and the mean follow-up period was 3.7 years (±0.9). The minimum follow-up period was 2.0 years. Primary outcome measures were the absolute constant-score (CS), the subjective shoulder value (SSV) as well as the ability to return to sports. RESULTS: The mean CS in the SA group was 91.6 (±5.5) compared to 81.3 (±15.5) in the TS group (p = 0.04). The mean SSV after SA repair was 96.9 (±4.6) compared to 80.0 (±20.8) after TS repair (p = 0.01). Both scores showed significantly higher standard deviations within the TS group (p < 0.05). Twelve of eighteen patients (67 %) were able to return to their overhead sports without restrictions (5/9 in the SA group and 7/9 in the TS group; p > 0.05). Fourteen of twenty-four patients (58 %) achieved their preinjury sports levels (8/12 in the SA group and 6/12 in the TS group; p > 0.05). CONCLUSIONS: Superior objective and subjective shoulder function was obtained following arthroscopic SA repair compared to arthroscopic TS repair of isolated SLAP-2 lesions. In addition, results of SA repair were more predictable. However, nearly half of the athletes did not achieve full return to sports regardless of the applied technique of refixation.

Graft-dependent differences in the ligamentization process of anterior cruciate ligament grafts in a sheep trial.

PURPOSE: The structural properties of the healing ligament are the determining factor for the stability of the reconstruction before, during, and after osseous integration of anterior cruciate ligament grafts. Over the course of ligamentization, the stability of synovialized grafts seems lower than that of non-synovialized patellar tendon grafts. METHODS: In an animal study on 42 sheep, 21 non-synovialized grafts (patellar tendon) and 21 synovialized grafts (flexor digitorum superficialis tendon) were performed to replace the anterior cruciate ligament. After 6, 12, and 24 weeks, 7 animals from each group were euthanized and investigated. Anteroposterior stability of the knee was assessed. After removal of all other soft tissues, the ACL was loaded to failure. Histology and histological analysis of the intra-articular graft region was then performed. RESULTS: There were no significant differences in the translation test comparing synovialized and non-synovialized grafts. After 6, 12, and 24 weeks, all transplants failed in the tensile test due to interligamentous rupture or avulsion. After 6 weeks, transplants did not show significant biomechanical differences. Load to failure and stiffness of the patellar tendon was more than twice those of synovialized tendon (P = 0.002) after 12 weeks. Histology revealed necrosis in patellar tendon specimens after 12 weeks. A significant increase in load to failure was determined in synovialized ligament grafts between 12 and 24 weeks (P = 0.005). Its load capacity then tended to be higher than that of patellar tendon grafts. CONCLUSION: The stability of synovialized ligament grafts is significantly lower than that of non-synovialized patellar tendon grafts after 12 weeks. This difference is compensated after 24 weeks. The significantly lower load to failure of synovialized compared with non-synovialized grafts after 12 weeks may be clinically relevant for the rehabilitation process of anterior cruciate ligament grafts in humans.

Revision of anterior cruciate ligament reconstruction with patellar tendon allograft and autograft: 2- and 5-year results.

INTRODUCTION: The most common failure reasons of an anterior cruciate ligament (ACL) graft are incorrect positioning of the drill channels and insufficient fixation. In many cases, one-stage revision with patellar tendon graft and the appropriate corrections are possible. For previous use of the ipsilateral patellar tendon third, an allograft seems favorable for reconstruction. So far, no study compared the results of revision surgery of autologous versus allogenous patellar tendon grafts for revision surgery of the ACL in a 5-year follow-up. MATERIALS AND METHODS: A retrospective study was conducted to analyze the clinical outcome and stability results 2 years (19.2 ± 5.8 months) and 5 years (68.8 ± 6.8 months) after revision of ACL reconstruction using middle-third patellar tendon allografts and autografts. The allografts were cleansed by mechanical means only. There were 15 patients in the allograft group and 14 in the autograft group. Patients with isolated re-rupture of the ACL graft were included in the study. Clinical results were evaluated by International Knee Documentation Committee 2000 forms (IKDC), Lysholm score, Tegner activity score, and visual analog scale. Stability was evaluated by means of KT-1000 arthrometer, Lachman test, and pivot-shift test. Location of drill holes was evaluated radiologically. Gonarthritis was graded according to Kellgren and Lawrence on the basis of radiographs. RESULTS: There were no significant differences between the two groups in anterior translation, manual examination for stability, IKDC 2000 findings, Tegner activity score, or Lysholm score. Extension deficits were more frequent in the autograft group at the first follow-up (P = 0.010). Lateral gonarthritis and femoral tunnel widening were more common in the allograft group at the second follow-up (P = 0.049 and P = 0.023, respectively). Pain on walking downhill was significantly more frequent in the allograft group at the second follow-up (P = 0.027). CONCLUSIONS: The functional results with allografts that had not undergone irradiation or chemical sterilization were comparable to those with autografts in ACL revision surgery. Allografts represent a good alternative to autogenous patellar tendons in revision surgery.

10-Year Survival Rates After High Tibial Osteotomy Using Angular Stable Internal Plate Fixation: Case Series With Subgroup Analysis of Outcomes After Combined Autologous Chondrocyte Implantation and High Tibial Osteotomy.

BACKGROUND: Good-to-excellent midterm results after high tibial osteotomy (HTO) to treat medial compartment cartilage defects or osteoarthritis (OA) have been published, but little is known about long-term survival rates in terms of conversion to total knee arthroplasty (TKA) using angular stable internal plate fixation. PURPOSE: To determine TKA-free survival rates and functional and radiological outcomes at 10 years after HTO. A subgroup analysis of patients who underwent combined HTO and autologous cartilage implantation (ACI) was also performed. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Included were 125 patients with a mean follow-up of 9.90 ± 2.25 years; 90 patients underwent HTO for medial OA, and 35 patients underwent ACI and HTO for medial focal cartilage defects. Functional outcome measures included visual analog scale (VAS) for pain, Lysholm, International Knee Documentation Committee (IKDC), and Knee injury and Osteoarthritis Outcome Score (KOOS) subscales and KOOS4 (average of 4 KOOS subscales: Pain, Symptoms, Sport, and Quality of Life). Radiological outcomes included lateral distal femoral angle, medial proximal tibial angle, and joint line convergence angle. RESULTS: Overall, 16 patients required conversion to TKA at a mean 86.75 ± 25.73 months (10-year survival rate, 87.2%). Only 2 patients in the HTO+ACI subgroup required a conversion to TKA (10-year survival rate, 94.3%). The complication rate for all patients was 8.8%. In both the HTO and HTO+ACI subgroups, VAS pain levels decreased and Lysholm scores increased significantly from pre- to postoperatively (P < .001). A higher preoperative Tegner score led to a significantly lower risk for conversion to TKA (P = .001), and a preoperative body mass index of ≥35 was associated with a significantly higher risk (P = .019), as was female sex (P = .046). Radiological parameters remained within physiological ranges. The postoperative joint line conversion angle did correlate with postoperative functional outcome but not with TKA conversion. CONCLUSION: Long-term results of HTO for medial compartment OA or cartilage defects with underlying varus deformity were good to excellent. In particular, patients who underwent HTO+ACI presented excellent long-term survival rates. HTO, therefore, delays or prevents TKA implantation, especially in young, active patients with medial compartment damage.

Validation of a measurement device for instrumented quantification of anterior translation and rotational assessment of the knee.

PURPOSE: A test setup for clinical use in the awake and non-anesthetized patient measuring anteroposterior translation and rotation of the knee joint is the subject of validation. METHODS: A measuring device featuring fixation of the foot at 30° of knee flexion with varus/valgus stress posts for the knee was developed. Tibial rotation (external/internal) was imposed with a torque of 2 Nm on the footrest with the ankle locked in dorsiflexion. Anterior translation of the tibia in relation to the femur was measured with a commercially available arthrometer. Measurements were performed in a neutral position, internal rotation, and external rotation. Intrarater and inter-rater reliability was validated in 10 healthy volunteers (Cronbach α). We examined 10 patients with isolated anterior cruciate ligament (ACL) rupture, as well as 10 patients with ACL rupture plus medial instability and 10 patients with additional lateral instability. Side-to-side differences were used for calculation. RESULTS: Comparison of healthy volunteers and subjects with isolated ACL rupture showed significant differences: internal rotation, 0.79 mm and 2.46 mm, respectively (P = .001); neutral position, 0.4 mm and 3.35 mm, respectively (P < .0001); and external rotation, 0.29 mm and 2.5 mm, respectively (P = .003). Significant differences (P = .008) were found between isolated ACL rupture and ACL rupture plus medial instability by use of the ratio of anterior translation in external rotation versus the neutral position. Inter-rater reliability was 0.948 in 10 healthy volunteers and 0.981 in 10 subjects with unilateral ACL rupture. Intrarater reliability in the volunteers was 0.829. CONCLUSIONS: By use of the developed measurement device, the "Laxitester" (ORTEMA Sport Protection, Markgroeningen, Germany), objective differentiation between isolated ACL rupture and ACL rupture plus additional medial instability is possible. Values for anterior translation are reliable and reproducible by different examiners and by the same examiner at different times. CLINICAL RELEVANCE: The Laxitester allows objectification of medial instability in combination with ACL injuries and provides a reference regarding the need for additional medial stabilization. Compared with the isolated measurement of anteroposterior translation, knee instability can be assessed in a more differentiated manner.

Problems of bridging plate fixation for the treatment of forearm shaft fractures with the locking compression plate.

INTRODUCTION: Treatment of diaphyseal forearm fractures by open reduction and internal plate fixation is a well-accepted strategy. In a variety of fracture localizations, the use of bridging plate fixation with locking compression plates (LCP) has been shown to improve biomechanical and biological characteristics. Only very limited clinical data are available on bridging plate fixation using LCPs for the treatment of diaphyseal forearm fractures. The aims of this study were to assess both clinical outcomes of LCP fracture treatments, and the implant-specific advantages and disadvantages. METHOD: The study consisted of 53 patients. All relevant data were extracted from the medical reports and radiographs. Of the 53 patients, 39 completed the disabilities of the arm, shoulder and hand (DASH) questionnaire and 35 patients were available for clinical examination. The mean time of follow-up was 23.3 months. RESULTS: Thirty-nine fractures of the radius and 45 fractures of the ulna were treated with 3.5 mm LCPs. Due to a fracture non-union, four patients underwent a second operation. In 13 patients, hardware had already been removed at the time of follow-up. Complete documentation of the removal operation was available for ten patients; in seven of these, procedures difficulties occurred. Mean ranges of motion were 138°, 141° and 162° for elbow flexion-extension, wrist flexion-extension and pronation-supination, respectively. The mean DASH score was calculated at 14.9. CONCLUSION: In conclusion, our data show that clinical and functional outcomes of LCP plating of diaphyseal forearm fractures are comparable to the use of conventional implants. However, implant-specific problems during hardware removal must be considered.

Correlation of radiographic and navigated measurements of TKA limb alignment: a matter of time?

Valid and reproducible measurements of limb alignment are prerequisites for planning, performing and evaluating TKAs. Although navigation systems have been shown to be reproducible tool for intraoperative TKA alignment measurements, particular doubt has been raised on the correlation with postoperative radiographic measurements. The aim of the present study was to evaluate whether the association of postoperative radiographic and navigation measurements of limb alignment was dependent on the time of acquisition. For this purpose, we retrospectively compared two groups of patients who underwent computer-assisted cemented TKA for osteoarthritis of the knee. Intraoperative navigation measurements (OrthoPilot™, Aesculap, Tuttlingen, Germany) were recorded before any cuts were made and again after implants had been placed. Long leg standing radiographs were acquired preoperatively in both the groups and either 2 weeks or 3 months postoperatively and AP limb alignment measurements were correlated with those of the respective navigation assessments. Preoperative deformity was similar in both the groups and correlation between radiographic and navigation measurements was excellent in both groups (ρ = 0.845 and 0.945, respectively). However, both mean and maximum discrepancies between radiographic and navigation measurements of leg alignment were significantly larger when radiographs were obtained 2 weeks (2.6° ± 2.1°, max. 10°) when compared with 3 months (1.8° ± 1.4°, max. 5°) postoperatively (P = 0.026). Accordingly, correlation between radiographic and navigation measurements was poor when radiographs were obtained 2 weeks postoperatively (ρ = 0.26, n.s.) but in the range of preoperative assessments when obtained 3 months postoperatively (ρ = 0.841, P < 0.001). Radiographic and navigation measurements of TKA limb alignment correlate well preoperatively. Equally good correlations can only be achieved when postoperative radiographic measurements are delayed to a time when more patients achieve full or near-full extension and are able to bear full weight leading to more valid radiographs.

Viscoelasticity and histology of the human cartilage in healthy and degenerated conditions of the knee.

BACKGROUND: There are many studies on osteoarthritis, but only a few studies deal with human arthrosis, comparing the mechanical properties of healthy and diseased samples. In most of these studies, only isolated areas of the tibia are examined. There is currently only one study investigating the complete mapping of cartilage tissue but not the difference between instantaneous modulus (IM) in healthy and diseased samples. The aim of this study is to investigate the relationship between the biomechanical and histological changes of articular cartilage in the pathogenesis of osteoarthritis. METHODS: The study compared 25 tibiae with medial gonarthrosis and 13 healthy controls. The IM was determined by automated indentation mapping using a Mach-1 V500css testing machine. A grid was projected over the sample and stored so that all measurements could be taken at the same positions (100 ± 29 positions across the tibiae). This grid was then used to perform the thickness measurement using the needle method. Samples were then taken for histological examinations using a hollow milling machine. Then Giemsa and Safranin O staining were performed. In order to determine the degree of arthrosis according to histological criteria, the assessment was made with regard to Osteoarthritis Research Society International (OARSI) and AHO scores. RESULTS: A significant difference (p < 0.05) could be observed in the measured IM between the controls with 3.43 ± 0.36 MPa and the samples with 2.09 ± 0.18 MPa. In addition, there was a significant difference in IM in terms of meniscus-covered and meniscus-uncovered areas. The difference in cartilage thickness between 2.25 ± 0.11 mm controls and 2.0 ± 0.07 mm samples was highly significant with p < 0.001. With regard to the OARSI and AHO scores, the samples differed significantly from the controls. The OARSI and AHO scores showed a significant difference between meniscus-covered and meniscus-uncovered areas. CONCLUSIONS: The controls showed significantly better viscoelastic behavior than the arthrotic samples in the measured IM. The measured biomechanical values showed a direct correlation between histological changes and altered biomechanics in gonarthrosis.

Mortality in patients with pelvic fractures: results from the German pelvic injury register.

BACKGROUND: Pelvic and acetabular fractures are rare injuries and account for approximately 3% to 8% of all fractures. Often the result of high energy blunt trauma, most of the patients sustaining pelvic injuries are at high risk of associated injuries strongly influencing outcome and survival rates. Because of anatomic differences it has been suggested that pediatric pelvic fractures are different injuries as compared with that of adults. However, this has been controversially discussed. Aim of this multicenter register study was to identify similarities and differences between pediatric and adult pelvic trauma and evaluate the influence of changes in medical treatment by comparison of two treatment periods. METHODS: In this multicenter register study, data of 4,291 patients treated from 1991 to 1993 (n = 1,723) or 1998 to 2000 (n = 2,568) for pelvic fractures in one of the 23 participating hospitals were evaluated for age, gender, Injury Severity Score (ISS), Hannover Polytrauma Score (PTS), fracture type (using Tile's classification), peripelvic soft tissue injury, need for emergency measures, mortality, cause of death, and need for operative stabilization. We compared the patients' characteristics of the two treatment periods and pediatric with adult pelvic injuries. Statistical analysis was performed using SAS software. RESULTS: There was no difference in terms of ISS, PTS, and presence of peripelvic soft tissue injuries between the two observation periods. Mortality rate dropped significantly from 7.9% to 5% (p < 0.0001) in the latter treatment period. Death was directly attributed to the pelvic injury in 11% from 1991 to 1993. This rate dropped significantly to 7% in the period from 1998 to 2000 (p = 0.020). A type fractures decreased from 61.1% (1991-1993) to 57.1% (1998-2000) of patients (p = 0.028) and except for these simple fractures there was a significant overall trend toward surgical treatment. Multivariate analysis revealed ISS, PTS, concomitant soft tissue injuries, and need for emergency measures as independent risk factors for death whereas surgical stabilization and treatment in the latter treatment period were associated with an increased survival rate. We found no difference between the adult and the pediatric group in terms of ISS and concomitant peripelvic soft tissue injuries. Children were less likely to receive surgical treatment (19.4% vs. 34.5%, p < 0.0001) but requirement for emergency measures was higher in the pediatric group (17.9% vs. 11.1%, p = 0.033). Moreover, we found no significant differences in mortality between both groups (6.1% vs. 8.2%, p = 0.28). Multivariate analysis showed age