Incidence of Distal Femoral Periprosthetic Fractures after Total Knee Arthroplasty.

BACKGROUND: The incidence of distal femoral periprosthetic fractures associated with total knee arthroplasty (TKA) has been reported as 0.3% to 2.5%. This study examined the incidence of distal femoral periprosthetic fractures at one hospital over a 16-year period. We hypothesized that the incidence of these fractures would be lowered after the introduction of lugged femoral implants and insertion of a distal femoral intramedullary bone graft during TKA. METHODS: From 1994 to 2010, 4,943 primary TKAs were performed. Following these TKA operations, 21 distal femoral fractures occurred. The surgical technique and implant design changed during this interval. Lugged femoral implants were introduced in 2000. Intramedullary bone grafting of the distal femoral intramedullary guide hole was introduced in 2002. RESULTS: The incidence of distal femoral periprosthetic fracture in this series of 4,943 TKA operations was 0.42% (21/4943). Six fractures occurred in 1,236 knees with femoral implants without femoral fixation lugs (0.49%). Fifteen fractures occurred in 3,707 knees with femoral implants with femoral fixation lugs (0.40%). Eight fractures occurred in 1,653 knees that did not have intramedullary bone grafts (0.48%). Thirteen fractures occurred in 3,290 knees that had intramedullary bone grafts (0.40%). Two fractures occurred in 417 knees with lugged femoral implants and no bone graft (0.48%). CONCLUSIONS: In this series, there was no significant difference in the incidence of distal femoral periprosthetic fractures associated with adding fixation lugs to the femoral implant and filling the femoral intramedullary hole with bone graft.

Do osteotomies of the proximal femur still have a role?

Trochanteric valgus and varus correction osteotomies have been described with or without associated rotational correction. In the last decade, new techniques have been described, including femoral neck osteotomy, femoral head reorientation, relative neck lengthening, greater or lesser trochanter distalization, and femoral head reduction osteotomy. While the overall number of femoral osteotomies in the young patients has decreased because of the efficacy of primary total hip arthroplasties, those osteotomy techniques may expand the indications for femoral osteotomies in select patients who meet the indications.

Periacetabular osteotomy after failed hip arthroscopy for labral tears in patients with acetabular dysplasia.

BACKGROUND: Chronic mechanical overload of the acetabular rim may lead to acetabular labral disease in patients with hip dysplasia. Although arthroscopic debridement of the labrum may provide symptomatic relief, the underlying mechanical abnormality remains. There is little information regarding how the results of periacetabular osteotomy are affected by a prior primary treatment for labral disease in the presence of acetabular dysplasia. METHODS: In a retrospective matched-cohort study, seventeen patients who had arthroscopic labral debridement prior to periacetabular osteotomy (the arthroscopy group) were compared with a control group of thirty-four patients who did not undergo arthroscopic labral debridement prior to periacetabular osteotomy (the non-arthroscopy group). Two control patients were randomly matched to each experimental patient from a pool of controls. Functional outcomes were assessed with use of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Failure of periacetabular osteotomy was defined as conversion to a total hip replacement. RESULTS: Changes in the preoperative and postoperative WOMAC scores of arthroscopy and non-arthroscopy patients were comparable, and the differences between the two treatment groups were not significant. We were unable to show a significant difference between the seventeen arthroscopy and thirty-four non-arthroscopy patients with regard to the risk of having to undergo a total hip replacement. CONCLUSIONS: When arthroscopic labral debridement fails to improve symptoms in patients with labral disease secondary to acetabular dysplasia, periacetabular osteotomy may still be considered as a joint-preserving procedure that can achieve good functional results.

Epiphyseal reperfusion after subcapital realignement of an unstable SCFE.

We present a case of epiphyseal reperfusion in a 12-year-old boy following subcapital realignment of a unstable slipped capital femoral epiphysis. The case demonstrates that even if delayed, anatomical surgical realignment of the femoral head can be successful in preserving or reestablishing blood flow to the femoral epiphysis.

Spatiotemporal parameters of gait after total hip replacement: anterior versus posterior approach.

The objective of this preliminary study was to examine possible differences in gait characteristics between subjects operated by way of a direct anterior approach and a posterior approach for primary total-hip arthroplasty, and age-matched healthy controls. Fifty-one subjects walked over an instrumented mat at two different speeds (self-selected comfortable and faster than normal) and spatiotemporal gait parameters were calculated using a validated methodology. Despite excellent clinical and radiographic scores, and irrespective of surgical approach, patients demonstrated an impaired walking performance (lower velocity and shorter step lengths) during fast walking, but not at the self-selected comfortable speed compared with healthy controls. Subjects operated with the posterior approach reported significantly higher stiffness than anterior subjects, but similar pain and function. Six months after total arthroplasty for primary osteoarthritis of the hip, gait characteristics were comparable between subjects having received the direct anterior approach and the posterior approach.

The history of the anterior approach to the hip.

The anterior approach is a safe, reliable, and feasible technique for total hip arthroplasty, permitting optimal soft tissue preservation. Since Hueter first described this interval, many surgeons have approached the hip anteriorly to perform a myriad of surgical procedures. The anterior approach allows optimal muscle preservation, and it is a truly internervous approach to the hip. An understanding of the evolution of the anterior approach to the hip will help the orthopedic community understand these advantages and why so many have used this approach in the treatment of hip pathology and for the implantation total hip arthroplasty.

Does hip resurfacing require larger acetabular cups than conventional THA?

UNLABELLED: Hip resurfacing is femoral bone preserving, but there is controversy regarding the amount of bone removed at the acetabular side. We therefore compared the implanted acetabular cup sizes in primary THAs between two resurfacing devices and a conventional press-fit cup using a series of 2134 THAs (Allofit cup 1643 hips, Durom Hip Resurfacing 249 hips, and Birmingham Hip Resurfacing 242 hips). The effects of patient demographics and cup position in the horizontal plane also were assessed. After controlling for gender, patients were matched for height, weight, body mass index, and age. The mean size for Allofit cups was smaller than the sizes for Durom and Birmingham Hip Resurfacing cups in women (49.9 mm, 51.6 mm, 52.3 mm, respectively) and men (55.1 mm, 56.7 mm, 57.8 mm; respectively). Although patient height was associated with the implanted cup size, the cup position in the horizontal plane had no effect on the size used. Larger cups were used with hip resurfacing than for THA with a conventional press-fit cup. However, additional studies are needed to determine whether these small differences have any clinical implications in the long term. The association of cup size and patient height should be considered in future studies comparing component sizes among different implants. LEVEL OF EVIDENCE: Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Recombinant human bone morphogenetic proteins in the treatment of fractures.

Recently, several prospective randomized clinical trials have resulted in the publication of critical studies on the efficacy of recombinant human morphogenetic proteins BMP-2 (rhBMP-2) and BMP-7 (OP-1) in spinal fusion and fracture healing. The clinical use of BMPs is now in its infancy and understanding the mechanism and the appropriate application of these proteins is necessary for all practicing orthopedic surgeons. This article will revisit some of the early studies using rhBMPs and review the current literature on their role in fracture healing.