The round femoral stem provides a similar clinical outcome but more serious proximal stress shielding compared to the rectangular stem in cementless total hip arthroplasty without a shortening osteotomy in patients with Crowe type 2 or 3 hip dysplasia.

OBJECTIVES: This study aims to compare clinical and radiological follow-up results of a rectangular (SL-Plus®) or a round (Synergy®) femoral component in patients with Crowe type 2 or 3 hip dysplasia operated with total hip arthroplasty (THA) without a shortening osteotomy. PATIENTS AND METHODS: Between January 2012 and December 2017, a total of 34 hips of 30 female patients (mean age: 42.9±11.6 years; range, 24 to 66 years) were retrospectively analyzed. All patients were evaluated using the Harris Hip Score (HHS) and Visual Analog Scale (VAS) for pain pre- and postoperatively. Intra- and postoperative complications were noted. Evaluation criteria included leg length discrepancy, stem subsidence, bone atrophy or hypertrophy around the stem according to Gruen zones, operative time, and intraoperative blood loss. Correlation analysis of radiological, clinical findings, and stem size was performed. RESULTS: The mean follow-up was 61.3±27.2 months. The mean postoperative HHS was 89.3±6.2 vs. 93.1±9.1, and the mean VAS score 1±0.6 vs. 1±0.8 in round and rectangular stem groups at the final follow-up. No significant differences were detected between the groups in any of the evaluated parameters, except for a more severe degree of stress shielding observed in the round stem group. Round stem size was positively correlated with a more severe stress shielding (r=0.55, p=0.020). No patient had to be revised during the follow-up period. The overall complication rate was 9%. CONCLUSION: Successful and comparable results can be obtained with cementless THA in patients with high riding dysplastic hips implanting either of the femoral components, a rectangular or a round stem. Although the round stem was associated with more common proximal stress shielding, this was not associated with worse clinical outcomes.

Anterior cruciate ligament repair using dynamic intraligamentary stabilization provides a similarly successful outcome as all-inside anterior cruciate ligament reconstruction with a faster psychological recovery in moderately active patients.

OBJECTIVES: This study aims to comparatively evaluate early to mid-term clinical results of case-matched patient groups of primary repairs with dynamic intraligamentary stabilization (DIS) or all-inside anterior cruciate ligament (ACL) reconstruction (ACLR) by an independent group. PATIENTS AND METHODS: Between March 2015 and September 2018, a total of 16 patients operated for ACL injuries with the repair technique were retrospectively identified. Cases were stratified by treatment: DIS technique versus all-inside ACLR and matched at a ratio of 1:2. The ACLR patients were selected from a patient group with an injury-to-operation time interval of fewer than three months. A total of 32 patients were included in the all inside ACLR group. Pre-injury and postoperative International Knee Documentation Committee (IKDC) subjective score, Tegner and Lysholm scores had been obtained. Additionally, ACL-Return to Sport after Injury (ACL-RSI) scale scores, clinical results, and complications were noted. RESULTS: One (6%) patient in the DIS group and two (6%) patients in the ACLR group were lost-to-follow-up and, for a total of 45 patients, 15 in the DIS group and 30 in the ACLR group, were included in the study. The mean postoperative follow-up was 50.8±13.5 months and 48.2±11.4 months in the DIS and ACLR groups, respectively. The Tegner, Lysholm, and IKDC subjective scores were non-significantly different between the groups at any time points. The ACL-RSI scale scores were significantly higher at six (p<0.001) and 12 (p=0.01) months in the repair group. The pivot-shift test was negative in all cases postoperatively. One re-rupture occurred in each group. The reoperation rate at any cause was 25% for the repair and 10% for the ACLR group. CONCLUSION: Primary ACL repair using the DIS technique provides a similar clinical outcome to these by an all-inside ACLR technique in moderately active patients. The DIS technique is reliable and reproducible, and associated with an early and speedier psychological recovery in a carefully selected, non-athlete patient group as observed by an independent group.

A Higher Initial Tensioning Force of an ACL Graft Results in a Higher Graft Force After Screw Fixation Irrespective of the Screw Diameter: A Biomechanical Study.

BACKGROUND: The intra-articular graft force (IAGF) in anterior cruciate ligament reconstruction decreases quickly over the first hours after surgery. Nevertheless, little is known about whether the initial extra-articular tensioning force (EATF) and screw diameter affect the graft force after fixation. PURPOSE: To investigate the effects of different EATFs on the IAGF of a soft tissue graft fixated via a bioabsorbable interference screw over 100 minutes after fixation and to evaluate the effects of different screw diameters within 1 mm of the tunnel width during this process. STUDY DESIGN: Controlled laboratory study. METHODS: In this biomechanical study, a porcine quadruple-strand soft tissue graft was inserted into the tibial anterior cruciate ligament tunnel. On the extra-articular side, 3 loads were applied during retrograde insertion of the bioabsorbable interference screw (6, 7, and 8 mm): 20 N, 80 N, and maximum manual EATF (Nmax). Nine study groups consisting of 10 tibiae each were created to test the effects of different EATFs and screw sizes. The IAGF was measured up to 100 minutes after the EATF was released. RESULTS: An EATF ≥80 N resulted in a larger IAGF for all screw sizes at 100 minutes. There were no significant associations between the IAGF at 100 minutes and different screw diameters. Inserting the tibial screw significantly increased the IAGF in all groups, with the exception of Nmax applied in groups with 7- or 8-mm screws. When compared with the end of screw insertion, after the release of the EATF, the IAGF dropped by 55% to 77 % at 100 minutes. CONCLUSION: An initial EATF ≥80 N is associated with a significantly larger IAGF at 100 minutes in this cadaveric simulation. The IAGF in soft tissue grafts decreased substantially after the retrograde placement of an interference screw. A recommendation regarding screw diameter with respect to the IAGF cannot be given. CLINICAL RELEVANCE: To obtain a higher residual graft force after bioabsorbable interference screw fixation, an initial EATF ≥80 N should be applied according to this model. The significant decrease in graft force after the release of the EATF indicates that the reconstructed knee cannot be mechanically stabilized after the surgery.