TS Waters

BACKGROUND: Anterior knee pain following total knee arthroplasty is a common complaint and typically is attributed to the patellofemoral joint. The purpose of the present study was to compare the outcome of resurfacing and nonresurfacing of the patella, particularly with regard to anterior knee pain, and to clarify the indications for patellar resurfacing at the time of total knee arthroplasty. METHODS: We performed a prospective, randomized study of 514 consecutive primary press-fit condylar total knee replacements. The patients were randomized to either resurfacing or retention of the patella. They were also randomized to either a cruciate-substituting or a cruciate-retaining prosthesis as part of a separate trial. The mean duration of follow-up was 5.3 years (range, two to 8.5 years), and the patients were assessed with use of the Knee Society rating, a clinical anterior knee pain score, and the British Orthopaedic Association patient-satisfaction score. The assessment was performed without the examiner knowing whether the patella had been resurfaced. At the time of follow-up, there were 474 knees. Thirty-five patients who had a bilateral knee replacement underwent resurfacing on one side only. RESULTS: The overall prevalence of anterior knee pain was 25.1% (fifty-eight of 231 knees) in the nonresurfacing group, compared with 5.3% (thirteen of 243 knees) in the resurfacing group (p < 0.0001). There was one case of component loosening. Ten of eleven patients who underwent secondary resurfacing had complete relief of anterior knee pain. The overall postoperative knee scores were lower in the nonresurfacing group, and the difference was significant among patients with osteoarthritis (p < 0.01). There was no significant difference between the resurfacing and nonresurfacing groups with regard to the postoperative function score. Patients who had a bilateral knee replacement were more likely to prefer the resurfaced side. CONCLUSIONS: As the present study showed a significantly higher rate of anterior knee pain following arthroplasty without patellar resurfacing, we recommend patellar resurfacing at the time of total knee replacement when technically possible.

A 21-year-old man with known hereditary multiple exostoses presented with a 24-hour history of atraumatic bruising and swelling of the posterior thigh. A leaking popliteal pseudoaneurysm was diagnosed on ultrasonography and an emergency saphenous vein bypass graft procedure performed. The patient required a post-operative blood transfusion but otherwise made a full recovery. Vascular complications from osteochondromas are rare and include vessel displacement, stenosis, occlusion, arteriovenous fistulas and pseudoaneurysm formation. Pseudoaneurysms usually present as an enlarging mass behind the knee. Acute rupture of an occult popliteal pseudoaneurysm caused by a distal femoral exostosis has not been reported previously.

Slipping or recurrent dislocation of the patella is a condition “seen almost entirely in girls or women, and is due, in large part, to the fact that the line of pull of the quadriceps extensor muscle is not straight.” Eleven patients with this condition are the basis for this paper. “... it seems to be true that, if the patella has slipped out several times without special violence, it is an evidence of joint instability... and, while the slipping may be controlled by simple measures, the weakness usually remains, and the joint is unable to stand the strain of normal use. For this reason, although bandaging, braces for the knees, the correction of flat or pronated feet, should always be tried in the early stages of the trouble before the slipping has become frequent, comparatively little is to be expected in the way of permanency of relief from such measures.... The treatment which has been most satisfactory in meeting this condition is an operation in which the outer half of the patella tendon is reattached to the tibia well to the inside of the tubercle. In this way the angle in the muscle pull is lessened or entirely removed.... Of the eight operations which have been performed in which this has been the chief feature, in seven no after-trouble has resulted, and the stability of the joints has made them equal to normal use.”

Introduction and Aims: Good clinical outcome can be expected following cementless total knee arthroplasty (TKA) provided there is early stability and bone ingrowth. Screws give excellent initial stability but provide a path for osteolysis. Screws also cause an irregularity of the tibial component surface which limits their use as a mobile bearing component. We hypothesise that early stability can be obtained with four peripheral pegs rather than screws. We present the results of such a tibial component at a minimum of two years in a cementless mobile-bearing TKA. Materials and Methods: We evaluated 200 knees in 173 patients. The average age at surgery was 72 years (range, 45–91 years) with 61% of cases in women. Patients were followed up for an average of 45.7 months (range 24 to 69 months). All radiographic and clinical scores were performed prospectively and recorded on a relational database. The components used were the cementless Low Contact Stress femoral component with the DuoFix MBT tibial tray (Depuy, Warsaw, Indiana, USA). The tibial tray was manufactured from cobalt-chrome with a central polished stem and four peripheral pegs. The underside, including the pegs, had a porous surface coated with 50 microns of hydroxyapatite. Results: After excluding patients who had died, or lost to follow up, 164 cases had a minimum 2-year follow-up. None of the tibial components have required revision. One patient (0.6%) required revision of the femoral component at 22 months for failure of bone ingrowth. There was one superficial infection which resolved with intravenous antibiotics. Two patients developed deep infections (1.2%) which resolved with arthroscopic lavage and antibiotics. One patient presented with bearing spin out at 3 months following surgery, and an exchange to a thicker tibial insert was performed. Average flexion at follow up was to 110°. The patients stated that they were satisfied with their knees in 141 out of 155 cases (91%). The mean score for pain at rest was 0.9 (0–10) and for activity related pain was 1.3. The average HSS score was 86/100 with 90% good or excellent results, compared with a preoperative score of 54/100. Lucent lines were seen in one tibial zone in ten knees (7%), and two zones in three knees (2.1%). There were lucent lines in one femoral zone in 13 cases and two zones in two cases. None of the lines were progressive, and all the surviving components were bone ingrown. Osteolysis was present in a single zone around one (0.7%) tibial component. One patient showed some femoral osteolysis in one zone (0.7%) and also had patellar osteolysis in one zone. Two patients had osteolysis in a single zone of the patella. Conclusion: This study shows that this design of mobile bearing tibial component provides good primary stability and bone ingrowth.

We report 5 cases of linked shoulder and elbow replacement (LSER) following failure of single-joint arthroplasty. Whilst total humeral replacement has been reported for treatment following resection for tumour we know of no reports of linked shoulder and elbow prostheses for arthropathy alone. Between May and December 2005, 2 patients with total elbow arthroplasty and 3 patients with total shoulder arthroplasty were revised to LSER for loosening of the long humeral stems or periprosthetic fracture. Custom-made prostheses were produced using computer-aided design and manufacture technology. There were no early complications including infection. All 5 patients reported early improvement of symptoms, with the ability to bear weight axially through the limb, restored. This technique avoids the problem of a stress riser between the stems of separate shoulder and elbow replacements and solves the problem of salvage of long-stemmed implants where no further humeral fixation is possible.