Medial Unicompartmental Knee Arthroplasty with a Fixed Bearing Implant.

Unicompartmental knee arthroplasty (UKA) is an alternative to total knee arthroplasty in isolated medial arthritis. UKA restores native tibial and femoral joint surfaces and corrects pre-disease limb alignment, by which natural knee biomechanics are restored, ensuring effective functional recovery. Proper patient selection and accurate surgical technique contribute to good functional outcome and long-term survival. The key steps of the procedure (as well as multiple tips and tricks) are demonstrated in the video article: (1) preoperative assessment and planning; (2) patient positioning and setup; (3) exposure; (4) instrument options and surgical technique; (5) distal femoral resection; (6) proximal tibial resection; (7) assessment of alignment and gaps; (8) finishing the femur-sizing, position, and posterior resection; (9) finishing the tibia-sizing and position; (10) trialing the implant; (11) implanting final components-cementing technique; (12) closure; and (13) rehabilitation. Following these surgical steps and principles will lead to excellent functional long-term results with a low revision rate and a minimum of complications.

Outcomes of a Fixed-Bearing, Medial, Cemented Unicondylar Knee Arthroplasty Design: Survival Analysis and Functional Score of 460 Cases.

BACKGROUND: Unicompartmental knee arthroplasty (UKA) is an alternative to total knee arthroplasty in isolated medial osteoarthritis (OA). However, despite satisfactory reports on the clinical performance, UKA revision rates are still concerning. This retrospective study reports on the long-term survivorship, functional outcomes, and reasons for revision in fixed-bearing UKA implant. METHODS: Between 2005 and 2013, 460 consecutive patients were treated with medial UKA in one center using a fixed-bearing UKA system. All patients were evaluated clinically and radiographically before surgery, and postoperatively at 6 weeks and 1 year. Between February and April 2016, all patients were reevaluated using the Oxford Knee Score. RESULTS: Mean follow-up was 5.5 (range, 2-11) years. The mean Oxford Knee Score was 43.3 (7-48), with 94.6% patients showing excellent or good outcomes. Eleven revisions (2.4%) occurred. The survivorship was 97.2% (95% confidence interval, 96.2%-99.2%) and 94.2% (95% confidence interval, 86.8%-97.5%) at 5 and 10 years, respectively, with revision of any implant component for any reason as the end point. The causes for revision were infection (4 cases, 0.9%); lateral pain due to overload (2 cases, 0.4%); progression of OA in the lateral compartment (2 cases, 0.4%); patellar pain with patellar chondropathy (2 cases, 0.4%); and severe synovitis (1 cases, 0.2%). There were no reoperations or revisions for component loosening, instability, component wear, or periprosthetic fracture. CONCLUSION: A fixed-bearing UKA system is a good treatment option for medial end-stage OA. Satisfactory functional results were achieved with low incidence of complications and revisions.

The M6-C Cervical Disk Prosthesis: First Clinical Experience in 33 Patients.

STUDY DESIGN: Retrospective study. OBJECTIVE: To determine the short-term clinical succesrate of the M6-C cervical disk prosthesis in primary and secondary surgery. SUMMARY OF BACKGROUND DATA: Cervical disk arthroplasty (CDA) provides an alternative to anterior cervical decompression and fusion for the treatment of spondylotic radiculopathy or myelopathy. The prevention of adjacent segment disease (ASD), a possible complication of anterior cervical decompression and fusion, is its most cited--although unproven--benefit. Unlike older arthroplasty devices that rely on a ball-and-socket-type design, the M6-C cervical disk prosthesis represents a new generation of unconstrained implants, developed to achieve better restoration of natural segmental biomechanics. This device should therefore optimize clinical performance of CDA and reduce ASD. MATERIALS AND METHODS: All patients had preoperative computed tomography or magnetic resonance imaging and postoperative x-rays. Clinical outcome was assessed using the Neck Disability Index, a Visual Analog Scale, and the SF-36 questionnaire. Patients were asked about overall satisfaction and whether they would have the surgery again. RESULTS: Thirty-three patients were evaluated 17.1 months after surgery, on average. Nine patients had a history of cervical interventions. Results for Neck Disability Index, Visual Analog Scale, and SF-36 were significantly better among patients who had undergone primary surgery. In this group, 87.5% of patients reported a good or excellent result and 91.7% would have the procedure again. In contrast, all 4 device-related complications occurred in the small group of patients who had secondary surgery. CONCLUSIONS: The M6-C prosthesis appears to be a valuable addition to the CDA armatorium. It generates very good results in patients undergoing primary surgery, although its use in secondary surgery should be avoided. Longer follow-up is needed to determine to what measure this device can prevent ASD.

Passive mobilization after arthroscopic rotator cuff repair is not detrimental in the early postoperative period.

This prospective randomized study compares the clinical results of immediate passive mobilization versus delayed mobilization in the rehabilitation of rotator cuff repair during the early postoperative period. The mobilization group (79 patients) received immediate daily passive mobilization. The immobilization group (51 patients) was immobilized for 4 weeks until physiotherapy was started. Passive range of motion was noted preoperatively, at 6 weeks and 4 months. Strength was measured preoperatively and at 4 months. Constant-Murley, Simple Shoulder Test, SPADI and UCLA scores were noted at baseline and at 4 months. Ultrasonography was performed at 6 weeks to exclude early failures of repair. We noted no significant difference between the two groups regarding range of motion at 6 weeks and range of motion, strength and functional outcome scores at 4 months. Ultrasound didn't show a difference in healing at 6 w in either of both groups. Both rehabilitation protocols seem applicable as well as safe in the early post-operative phase.

Does cruciate retention primary total knee arthroplasty affect proprioception, strength and clinical outcome?

PURPOSE: It remains unclear what the contribution of the PCL is in total knee arthroplasty (TKA). The goal of this study was to investigate the influence of the PCL in TKA in relationship to clinical outcome, strength and proprioception. METHODS: Two arthroplasty designs were compared: a posterior cruciate-substituting (PS) and a posterior cruciate-retaining (CR) TKA. A retrospective analysis was performed of 27 CR and 18 PS implants with a minimum of 1 year in vivo. Both groups were compared in terms of clinical outcome (range of motion, visual analogue scale for pain, Hospital for Special Surgery Knee Scoring system, Lysholm score and Knee Injury and Osteoarthritis Outcome Score), strength (Biodex System 3 Dynamometer(®)) and proprioception (balance and postural control using the Balance Master system(®)). Each design was also compared to the non-operated contralateral side in terms of strength and proprioception. RESULTS: There were no significant differences between both designs in terms of clinical outcome and strength. In terms of proprioception, only the rhythmic weight test at slow and moderate speed shifting from left to right was significant in favour of the CR design. None of the unilateral stance tests showed any significant difference between both designs. There was no difference in terms of strength and proprioception between the operated side and the non-operated side. CONCLUSION: Retaining the PCL in TKA does not result in an improved performance in terms of clinical outcome and proprioception and does not show any difference in muscle strength. LEVEL OF EVIDENCE: III.

Navigated total knee arthroplasty: a radiological analysis of 42 randomised cases.

The purpose of this study was to evaluate the use of a navigation device in a cohort of 42 total knee arthroplasties (TKA). The patients were randomised into two groups. Total knee arthroplasties performed using the conventional technique formed the control group (21 knees); the experimental group included 21 knees performed with the aid of a computed navigation system. Postoperative mean values for the various measurements showed no significant difference in component alignment. However, the range of individual measurements for coronal and sagittal plane positioning was smaller in the navigated group, in which there were no outliers. Rotational alignment was not different between the two groups. This confirms the advantages and limitations of navigated TKA presented in larger studies.