The medial parapatellar approach in total knee arthroplasty is arguably the most common approach, but the subvastus approach is less insulting to the quadriceps mechanism.

A single centre, randomized controlled trial was conducted in a metropolitan hospital to investigate whether the subvastus approach afforded better outcomes than the medial parapatellar approach. Ninety participants with knee osteoarthritis were randomized to either the subvastus or medial parapatellar approach. The primary outcome was the American Knee Society Score and secondary outcomes reported included pain, extension and flexion range of motion, quadriceps lag, girth, Oxford Knee Score, 3 meter timed up and go test, days to straight leg raise, surgeon perceived difficulty, operation duration, tourniquet duration and length of stay. Data were collected preoperatively, intra-operatively, days 1,2,3, discharge, 6 weeks and 6, 12 and 18 months post operatively.

Analysis was undertaken on 76 participants revealing no significant difference with the primary outcome (p=0.076; MP 167.3±36.6; SV 153.1±36.6) or any other outcome except for surgeon perceived difficulty, which favored the medial parapatellar approach (p=0.001; MP 3.3/10±1.9; SV 5.4/10±2.3) and days to straight leg raise, which favoured the subvastus approach by 0.9 days (p=0.044; MP 2.8±1.9; SV 1.9±1.6).

The subvastus approach is technically more difficulty and offers no clinical benefit over the medial parapatellar approach.

Purpose: Many lateral malleolar fractures in patients with osteoporotic bone are rotationally unstable, requiring fixation stable in torsion with good fatigue properties, but without bulk due to the soft tissue constraints. The purpose of this study was to evaluate the torsional performance of a thin (1.5mm) plate with locked and non-locked constructs in a simulated osteoporotic lateral malleolus fracture.

Method: A transverse fracture gap to mimic comminution was created in (15 lb/ft3) density foam. 3 bicortical unlocked screws were used proximal to the fracture in a 5 hole thin (1.5mm) plate for both constructs. Distally, two screws that did not breach the far cortex (12mm) were placed as locked in one group and unlocked in the other. The constructs were loaded in torsion at 1 Hz at 7.5/0.75 in-lbf (0.85/0.08 N-m) of torque. A torsional fatigue failure was defined as either a fracture of the plate, screw pull-out, or construct rotation 10 degrees beyond the maximum initial rotational displacement. Testing was conducted until construct failure or run-out of 300,000 cycles.

Results: The thin plate constructs with locked distal screws showed significantly improved fatigue properties (p< 0.00001). None of the locking plate constructs failed prior to the 300,000 cycle end point. In stark contradistinction, all of the non-locked contructs failed at an average cycle count of only 9,541 (range 1,000 – 23,000 cycles). The failure mode for each of the non-locked constructs was pull-out of the distal screws.

Conclusion: These results indicate that the use of a thin plate with locking capability provides a significant advantage over non-locked constructs in fatigue performance in areas of poor bone density subjected to torsional loads, such as the lateral malleolus.

This prospective randomized multicenter study compares two methods of bone defect treatment in tibial plateau fractures: a bioresorbable calcium phosphate paste (Alpha-BSM) that hardens at body temperature to give structural support versus Autogenous iliac bone graft (AIBG).

One hundred and eighteen patients were enrolled with a 2:1 randomization, Alpha-BSM to AIBG. There was a significant increased rate of non-graft related adverse affects and a higher rate of late articular subsidence (three to nine month period) in the AIBG group.

A bioresorbable calcium phosphate material is recommended in preference to the gold standard of AIBG for bone defects in tibial plateau fractures.

This prospective randomized multicenter study was undertaken to compare two methods of bone defect treatment: a bioresorbable calcium phosphate paste (Alpha-BSM –DePuy, Warsaw, IN) that hardens at body temperature to give structural support and is gradually resorbed by a cell-mediated bone regenerating mechanism versus Autogenous iliac bone graft (AIBG).

One hundred and eighteen adult acute closed tibial plateau fractures, Schatzker grade two to six were enrolled prospectively from thirteen study sites in North America from 1999 to 2002. Randomization occurred at surgery with a FDA recommendation of a 2–1 ratio, Alpha BSM (seventy-eight fractures) to AIBG (forty fractures). Only internal fixation with standard plate and screw constructs was permitted. Follow-up included standard radiographs and functional studies at one year, with a radiologist providing independent radiographic review.

The two groups exhibited no significant differences in randomization as to age, sex, race, fracture patterns or fracture healing. There was however, a significant increased rate of non-graft related adverse affects in the AIBG group. There was an unexpected significant finding of a higher rate of late articular subsidence in the three to nine month period in the AIBG group.

Recommendations for the use of AIBG for bone defects in tibial plateau fractures should be discouraged in favor of bioresorbable calcium phosphate material with the properties of Alpha BSM. We believe further randomized studies using AIBG as a control group for bone defect support of articular fractures are unjustified.

A bioresorbable calcium phosphate material is recommended in preference to the gold standard of AIBG for bone defects in tibial plateau fractures.

Funding: DePuy, Warsaw, IN.