Introduction

Up to 2% of total knee arthroplasties (TKA) are still complicated by infection. This leads to dissatisfied patients with poor function, and has far-reaching social and economic consequences. The challenge in these cases is the eradication of infection, the restoration of full function and the prevention of recurrence.

We report the outcome of prosthesis sparing early aggressive debridement in the acutely infected TKA.

Introduction: Up to 2% of total knee arthroplasties (TKA) are still complicated by infection. This leads to dissatisfied patients with poor function, and has far-reaching social and economic consequences. The challenge in these cases is the eradication of infection, the restoration of full function and the prevention of recurrence. We report the outcome of prosthesis sparing early aggressive debridement in the acutely infected TKA.

Methods: We studied 29 consecutive patients referred with acutely infected TKA (18 primaries, 11 revisions) which occurred within 6 weeks of the index operation or of haematogenous spread. Microbiology confirmed bacterial colonization in all cases with 20 early postoperative infections and 9 cases of acute haematogenous spread. All patients underwent aggressive open debridement, a thorough synovectomy and a change of insert. Antibiotics were continued until inflammatory markers and the plasma albumin concentration returned to within normal limits.

Results: Three patients required multiple washouts. 8 patients needed a two stage revision. 21 patients returned to their expected functional level without removal of the implants and with no radiographic evidence of prosthetic failure. At a minimum 2 years follow-up, we had a 72% infection control rate. The outcome was significantly better in patients treated in the first 120 hours after presentation.

Discussion and Conclusion: Our data suggests that there is a role for early aggressive open debridement in acute infections after TKA with an excellent chance of prosthesis salvage.

Purpose: To determine the effect of the ossific nucleus on avascular necrosis (AVN) of the hip in the treatment of hip dislocation.

Methods: A systematic review was performed in MED-LINE, EMBASE, DARE, and Cochrane Library. Two independent reviewers evaluated all articles. Interrater agreement was determined by the kappa statistic. Quality of evidence was evaluated by the GRADE statement. A meta-analysis was performed on the main outcome, AVN 2 years after reduction.

Results: 6 observational studies met the inclusion criteria. Inconsistency was found in that half of the studies reported a protective effect of the ossific nucleus, whereas half of the studies did not. A meta-analysis of all studies (415 patients) showed no statistical significant effect of the ossific nucleus on the development of AVN, with 42 (17%) cases of AVN in infants with the ossific nucleus present at reduction compared with 47 (28%) in the group without a ossific nucleus (RR 0.60, 95% CI 0.28 to 1.27). If only radiographic changes of grade ≥II were considered AVN, a significant difference in the prevalence of AVN was found, with 15 (6%) cases of AVN in infants with the ossific nucleus compared with 28 (20%) without the ossific nucleus (0.34, 0.17 to 0.67). Subgroup analysis showed that the presence of the ossific nucleus reduced the probability of AVN by 70% (0.30, 0.14 to 0.62) in case of a closed reduction, but no significant effect was found for open reduction (0.87, 0.50 to 1.54). All studies demonstrated methodological weaknesses compromising the quality of evidence.

Conclusion: We could not demonstrate a significant effect of the ossific nucleus on the development of AVN. The meta-analysis suggested that the ossific nucleus might have a protective effect against the development of more severe forms of AVN.

Purpose: Femoroacetabular impingement (FAI) is a precursor to osteoarthritis (OA) of the hip. To investigate the fate of impingement abnormalities we analyzed the contralateral hip in patients undergoing THA for advanced FAI. Our purpose was to determine the bilaterality of FAI abnormalities, and to describe the prognosis of these deformities.

Method: We reviewed 508 patients ≤50 years of age treated with THA. Radiographic review identified 70 hips that had OA secondary to FAI (71% cam, 5% pincer, 24% combined). Bilaterality was determined radiographically, and the fate of the contralateral hip was analyzed by determining radiographic presence and progression of OA, and the need for subsequent THA.

Results: 71% of the patients were male and the average age was 43.2 years. The contralateral hip was analyzed on radiographs over an average 9 year period (range, 4–30 years). 100% of the contralateral hips had radiographic features of FAI. 49 (70%) of the contralateral hips demonstrated degenerative disease. 14 had advanced OA at presentation, 41 had progressive joint space narrowing, 25 had progression of Tonnis OA grade and 26 underwent subsequent THA. Statistical analysis showed that alpha angle, LCEA, joint space width, and head-neck ratio have strong predictive value for subsequent THA (p< 0.05).

Conclusion: This study demonstrates that FAI abnormalities are commonly bilateral and are associated with OA progression in the majority of hips. Patients diagnosed with FAI should have both hips monitored, and joint preservation surgery or THA considered when appropriate.