[Cortical strut grafts, an alternative to conventional plating in periprosthetic fractures of the femur]

Periprosthetic fractures around the femoral stem: overcoming challenges and avoiding pitfalls

Management of periprosthetic fractures around the femoral stem after total hip arthroplasty (THA) represents a significant challenge and optimal treatment remains controversial. The most common treatment paradigm involves treating fractures around a well-fixed stem with osteosynthesis, whereas fractures around a loose stem require revision arthroplasty and those with poor bone require augmentation with bone graft. Paradoxically, the literature reports a higher rate of failure for osteosynthesis around prostheses considered to be well-fixed. Such a high rate of poor outcomes may result not only from difficult fracture fixation and compromised biologic healing, but also from unrecognized peri-implant pathology. Therefore, proper preoperative and intraoperative evaluation is key, and a subset of patients may benefit from alternative management. We review the appropriate methods for evaluation and treatment of Vancouver type B fractures with particular emphasis on avoiding missteps that can lead to failure.

[Reconstruction of metadiaphyseal bone defects of the femur with cortical strut allografts in periprosthetic bone loss]

OBJECTIVE

Biological augmentation and stabilization of high-grade bone defects with structural allografts from donor femur halfs.

INDICATIONS

Severe bone defects with aseptic loosening of hip prosthesis, periprosthetic femoral fracture or non-union, possibly even in cases of a healed infection.

CONTRAINDICATIONS

Local or systemic infection.

SURGICAL TECHNIQUE

The two modeled strut allografts are temporary fixed epiperiostal anterolateral and -medial with wire cerclages, while protecting the vascular supplying linea aspera of the femur. With the thus stabilized femur, the leg can be placed in the four-position in order to prepare the medullary canal of the revision prosthesis. Finally, the uncemented revision prosthesis is hammered in under successive tightening of the wire cerclages. With this "cracking technique", stem is stabilized and the grafts have repositioning, augmentative, and supportive function.

POSTOPERATIVE MANAGEMENT

Partial weight-bearing postoperatively for 12 weeks. X-ray control during surgery, 10 days postoperatively, after 6 and 12 weeks and every 1-2 years.

RESULTS

In four different studies, 123 patients were stabilized from December 1991 to June 2011 due to an extensive periprosthetic femoral bone defect and/or periprosthetic fracture, refracture, or non-union with strut allografts. After an average follow-up of 3.8 years (range 0.3-11 years), the average Harris Hip Score was 80.8 (range 44-100). During this time, there was 1 refracture, 103 stable stems, 20 fibrous stable stems, 9 patients with low graft resorption, and 122 patients with radiographic healing of the strut allografts based on classification according to Emerson et al. (Clin Orthop Relat Res 285:35-44, 1992).

[Intramedullary nailing of periprosthetic femoral fractures after revision for total knee endoprosthesis. Treatment of periprosthetic femoral fractures by inserted knee endoprostheis with intramedullary shaft by in situ lengthening of the prosthesis with specially prepared slotted hollow nails]

BACKGROUND

With the increasing number of revision operations after knee replacement a growing incidence of periprosthetic femoral fractures which are difficult to treat is observed.

MATERIAL AND METHODS

This retrospective study describes the operating procedure for osteosynthetic treatment of periprosthetic femoral fractures using a specially made slotted hollow nail which is engrafted with the purpose of in-situ lengthening of the prosthesis and thus becomes stably clamped. From 1999 to 2008 our patients have included 9 who were treated by this method. There were 5 male and 4 female patients with an average age of 63.4 years (range 47–80 years). Prerequisites for the performance of this operation are stability of the prosthesis and knowledge of the type of prosthesis or exact preoperative planning based on CT measurement of the thickness and length relationships.

RESULTS

It was possible to conduct a clinical and radiological follow-up examination of all 9 patients after an average time of 29.1 months (range 10–64 months). In all cases load-bearing stabilization of the fracture was confirmed.

CONCLUSION

In-situ coupling of an endoprosthesis with a slotted hollow nail represents a valuable treatment option for periprosthetic fractures.

Polyaxial Locked Implants in the Treatment of Type Vancouver B1 Periprosthetic Fractures of the Femur: Retrospective Clinical Examination in 58 Cases with Review of the Literature

We concluded a retrospective study of the outcomes of a consecutive series of Vancouver B1 and C femoral injuries using two specific locked implants. The study center is a dedicated trauma hospital with a large catchment area. Over a five-year period we treated 58 patients with a periprosthetic fracture of the femur with an angular stable plate, defined as the index procedure. The mean age at the index procedure was 72.4 years; 40 patients were female (69%). In 32 cases (55.2%) we saw a hip endoprosthesis, in 21 cases (36.2%) a knee endoprosthesis, and in five cases both (8.6%). Outcome measures were intra- and postoperative complications, bony union, degree of mobility and social status with comparison to the preoperative status, Barthel index, and timed ''up and go'' test. Union occurred in 56 cases (96.5%) after the index procedure. Three patients were bedridden before the injury; the remainder regained full weight-bearing status. The mean duration until full weight-bearing status in these patients was 8.6 weeks (4-13). Early implant failure with proximal dislocation of the screws occurred in two cases (3.5% revision rate). At follow up, 78% had maintained the same social status as before the injury. Fifty-two patients (89%) had regained their previous level of mobility. The mean Barthel index was 85 points (70-100) out of a possible 100, and improved from a mean of 35 points at the start of rehabilitation. It decreased on average by ten points compared to the preoperative status. The mean ''up and go'' time was measured as 21.4 s. In conclusion, polyaxial plates can achieve excellent surgical results. On the other hand, patients with this type of injury exhibit a clear deterioration in their social status, especially regarding lower limb motor function and self-independence.

Treatment of periprosthetic femoral fractures by effective lengthening of the prosthesis

The increasing number of hip and knee arthroplasties implies a greater likelihood of periprosthetic fractures and need for successful treatment options. We asked whether in situ effective lengthening of the indwelling prosthesis by a custom-made slotted hollow intramedullary nail provided a reasonable alternative to the established internal fixation techniques and prosthesis exchange. Between 1994 and 2005, we treated 25 patients (four male and 21 female; average age, 80 years) with a hip or knee periprosthetic fracture using this technique. Preconditions included a well-fixed prosthesis with a conical tip. In 23 hip cases a retrograde femur nail and in two knee fracture cases an antegrade nail were used for in situ lengthening of a femoral hip or knee implant stem. In all 25 cases, we used a preoperatively manufactured custom-made implant; in 20 patients, we recommended immediate mobilization by partial or full weightbearing. Eighteen of 25 patients were followed a minimum of 7 months (mean, 25 months; range, 7-31 months). Three patients died and four were lost to followup. We observed fracture healing in all patients, but one female patient had subsequent prosthesis loosening. The major complication rate was 6% (one of 18). We believe effective lengthening of the indwelling prosthesis by a custom-made slotted hollow intramedullary nail is a reasonable option for treating periprosthetic femoral fractures.

Periprosthetic fractures of the femur associated with hip arthroplasty

The nature of the treatment of periprosthetic fractures depends on the localisation, the stability of the prosthesis and the condition of the bone. The Vancouver fracture classification has proved to be of value in determining specific modes of treatment. The current review analyses the different therapeutic options resulting in a concept of fracture-specific treatment. In this report we propose an extended version of this classification in which periprosthetic fractures associated with endoprostheses anchored in the epiphysis or metaphysis, as well as interprosthetic fractures, are taken into consideration.