Proximal femoral allografts for reconstruction of bone stock in revision arthroplasty of the hip. A nine to fifteen-year follow-up

BACKGROUND

Revision of a femoral component in a patient who has severe bone loss is a complex problem that is likely to increase with the increasing numbers of patients who have multiple revision hip arthroplasties. A valuable option in such a situation is use of a long-stem prosthesis that is cemented to a proximal femoral allograft but not to the host bone.

METHODS

Between April 1984 and December 1989, sixty-three total hip arthroplasties in sixty consecutive patients were revised with a proximal femoral allograft-prosthesis construct. The average length of the allograft was 15 cm. The average age of the patients at the time of the revision was 62.5 years. All patients had undergone at least one previous total hip arthroplasty, and an average of 3.8 previous total hip arthroplasties had been performed in the series. Each patient was assigned a modified Harris hip score. Radiographs were examined for trochanteric union, allograft-host union, endosteal and periosteal resorption, component loosening, and fracture.

RESULTS

At an average of eleven years (range, nine years and four months to fifteen years) after the revision, forty-five patients were alive, fourteen patients had died, and one patient had been lost to follow-up. The patients who had died or had been lost to follow-up had had a total of fifteen allografts (24%) and had been followed for an average of five years and seven months (range, two years and four months to eight years). The average preoperative Harris hip score for the sixty-three hips was 30 points (range, 6 to 65 points). At the latest follow-up evaluation, the average score for the hips with the original graft in situ was 71 points (range, 47 to 95 points). Five hips failed because of infection, and four of them were successfully revised. Three hips failed because of aseptic loosening, at an average of ten years and three months; two were successfully revised, and the third was awaiting revision at the time of writing. An additional operation was performed in three hips with allograft-host nonunion and in two with dislocation. Success was defined as a postoperative increase in the Harris hip score of greater than 20 points, a stable implant, and no need for additional surgery related to the allograft at the time of the review. The success rate for all hips was 78% (forty-nine of sixty-three) after an average of nine years of follow-up. The success rate for the patients who were alive at the time of follow-up was 77% (thirty-seven of forty-eight hips) after an average of eleven years of follow-up.

CONCLUSIONS

The clinical and radiographic results at an average of eleven years after revision hip arthroplasty with a proximal femoral allograft are encouraging. This report represents our early experience; improvements in the technique have been made. We believe that this technique provides a viable option for treatment of the difficult problem of severe femoral bone loss.

The use of structural allograft for uncontained defects in revision total knee arthroplasty. A minimum five-year review

BACKGROUND

To our knowledge, the medium to long-term outcome after revision knee arthroplasty with structural allograft augmentation for reconstruction of uncontained defects has not been determined. The purpose of the present study was to assess the outcome for patients managed with such a procedure.

METHODS

We prospectively followed fifty patients who had fifty-two revision knee replacements with sixty-six structural grafts performed at three institutions. Twenty-nine knees (twenty-seven patients) were independently evaluated at a mean of 96.9 months (range, sixty to 189 months) by an investigator who had not been involved in the index procedure. Twelve knees (23%) had a repeat revision at a mean of 70.7 months (range, twenty-six to 157 months). The allograft was retained in two of these patients. Eleven patients died at a mean of ninety-three months (range, sixty-one to 128 months) after the procedure; the structural allograft and implants were intact, and the patients were not awaiting revision at the time of death.

RESULTS

Clinical evaluation revealed that the mean modified Hospital for Special Surgery knee score had improved from 32.5 points preoperatively to 75.6 points at the time of the review and the mean range of motion had increased from 60.5 degrees preoperatively to 88.6 degrees. Failure was defined as an increase of less than 20 points in the modified Hospital for Special Surgery knee score at the time of the review or the need for an additional operation related to the allograft. Thirteen knee replacements failed, yielding a 75% success rate. Five knees had graft resorption, resulting in implant loosening. Four knee replacements failed because of infection, and two knees had nonunion between the host bone and the allograft. Two knees (one patient) did not have a 20-point improvement in the knee score. The survival rate of the allografts was 72% (95% confidence interval, 69% to 75%) at ten years. On radiographic analysis, none of the surviving grafts had severe resorption, one had moderate resorption, and two had mild resorption. One knee had a loose tibial component, and three knees had nonprogressive tibial radiolucent lines. All four knees were asymptomatic.

CONCLUSIONS

Our results demonstrate that allografts used in revision knee replacement in patients with the difficult problem of massive bone loss have an encouraging medium-term rate of survival.

Development, test reliability and validation of a classification for revision hip arthroplasty

The objective of the study was to develop a valid and reliable classification system for failed hip arthroplasties. The study uses research principals derived from multi-attribute utility theory and consensus group techniques. The development of the severity measure was done in two phases. Phase I of the study included: (a) questionnaire development, (b) submission of the questionnaire to the respondents, (c) data synthesis of the responses and item reduction, and (d) classification development and inter-observer reliability testing. Phase II included: (a) resubmission of the instrument to the respondents for suggestions/feedback, (b) instrument revision by the co-investigators based on the respondents' second feedback, and (c) inter-observer reliability testing and intraoperative validity testing of the instrument. The questionnaires sought to capture expert opinion as to what clinical determinants obtained preoperatively (during patient interview, physical exam and review of plain radiographs - AP pelvis and hip lateral) that would in their clinical experience reveal intraoperative severity. There was an 80% (16/20) response rate from the outside experts invited to participate in the study. Based on item reduction and test retest analysis, a five-grade radiographic classification for the acetabulum as well as the femur was developed. This system was then reviewed by 13 of the initial outside experts (16, 80%) who participated in the first round. Inter-rater reliability testing of the final format of the classification revealed a weighted kappa statistic value of 0.88 between the two-blinded raters (inter-rater reliability) and 0.87 between the blinded raters and the reference standard (intraoperative validity). We conclude that the study developed a reliable and valid radiographic classification system for failed hip arthroplasty.

Total hip replacement for the dislocated hip

Replacing the dislocated hip is technically more challenging than replacing the subluxated hip. Overall, clinical and radiographic results have not been as good for hips that are completely dislocated. The surgical approach must allow for identification of the false and true acetabula, identification of the sciatic nerve, and lengthening of the leg. In patients with a dislocated hip who are managed with total hip replacement, coverage of the cup can be achieved by medialization, creation of a high hip center, or use of a structural graft. Bone grafting allows the cup to be placed in an anatomic position, provides bone stock for additional surgery, and restores leg length. Our results and the results of other authors confirm that these grafts remain intact for at least 10 years and restore bone stock for additional surgery. This is particularly important in this relatively young population.

Revision total hip arthroplasty with the use of structural acetabular allograft and reconstruction ring: a case series with a 10-year average follow-up

From 1980 through 1993, 20 consecutive massive structural acetabular allografts and reconstruction rings were performed in 19 patients. In all cases, the magnitude of the acetabular bone deficiency was such that the allograft supported >50% of the cup. The allograft was necessary to restore normal anatomy, bone stock, and leg length. Of the 19 patients who met the inclusion criteria, 7 subjects died of unrelated causes, and 3 subjects failed and underwent resection arthroplasty, 1 (8%) for graft resorption and 2 (15%) for recurrent dislocation. The remaining 9 patients (10 allografts) had a minimum follow-up of 5 years and average follow-up of 10.5 years. The cohort was analyzed using radiographic and outcome data collection questionnaires (AAOS/HKOD, WOMAC, SF-36). The study supports the use of massive structural allografts and reconstruction rings and achieves satisfactory results in 77% (10 of 13) of the patients. We believe these results reveal an impressive outcome for what used to be thought of as a salvage operation.

Complications of total hip arthroplasty: MR imaging-initial experience

PURPOSE

To investigate the use of standard magnetic resonance (MR) imaging sequences with simple parameter modifications for the detection and characterization of total hip arthroplasty (THA) complications.

MATERIALS AND METHODS

An initial phantom study was performed with cobalt-chrome and titanium prostheses to establish the imaging parameters for a subsequent clinical study. In the clinical study, coronal and transverse MR imaging of 14 THA prostheses was performed before and after intravenous contrast material administration in 12 patients who were being considered for revision arthroplasty. The images were reviewed for evidence of juxtaarticular or periprosthetic abnormalities, patterns of contrast enhancement, and quality of periprosthetic tissue depiction.

RESULTS

Phantom study results showed improved periprosthetic tissue depiction with use of thin sections, increased frequency-encoding gradient strength, and fast spin-echo sequences. The clinical study results demonstrated periprosthetic abnormalities in 11 cases: mechanical loosening in two cases (including one case with an associated periprosthetic fracture); granulomatosis, eight; and infection, one. In 100% of cases, tissue depiction around the femoral component was judged to be of "diagnostic quality." Tissue depiction around the acetabular component was of diagnostic quality in five (36%) cases. In all seven surgically confirmed cases, a correct diagnosis was made preoperatively with MR imaging.

CONCLUSION

By using simple modifications to standard MR imaging sequences, diagnostic-quality MR imaging of THA complications can be performed, particularly around the femoral prosthetic stem.

Minor column structural acetabular allografts in revision hip arthroplasty

A minor column (shelf) allograft is used for uncontained defects that involve less than 50% of the acetabulum. The prospectively collected records and radiographs of 47 patients (51 hips) who had undergone minor column structural acetabular allograft reconstruction during revision hip arthroplasty were reviewed. The purpose was to identify the long-term results (minimum 5 years) and factors that may influence longevity of the allograft and predispose the patient to subsequent acetabular component failure. The mean duration of followup was 119 months (range, 68-195 months). There was one perioperative death and six patients were lost to followup. Eleven patients (22%) required additional surgery. Three acetabular cups could not be revised successfully, despite multiple attempts, and the patients were treated with Girdlestone excisions. Eight patients underwent successful revision surgery with only three requiring a repeat structural allograft. Survival time for the acetabular cup as determined by Kaplan-Meier analysis was 153 months (95% confidence interval; range, 136-169 months). Cup failure was associated with more operative procedures performed before revision surgery (mean, 3.2 procedures), and failure to restore the vertical center of hip rotation to within 12 to 14 mm of the predicted value. The acetabular abduction angle was not a predictor for failure. The current study shows that good results can be achieved with structural acetabular allograft reconstruction with mid-term to long-term implant survival (cup aseptic survival, 80.4% and allograft re-construction survival, 94.1%), especially if there is restoration of near normal hip biomechanics.

Revision arthroplasty of the acetabulum with restoration of bone stock

Bone defects on the acetabular side are defined as contained (cavitary) and uncontained (segmental). Contained (cavitary) defects can be treated by morselized allograft bone with an uncemented cup if contact can be made with 50% host bone. If contact cannot be made with 50% host bone, the author prefers to use a ring and a cemented cup. Defining success as a stable implant, no additional surgery, and improvement in hip score of at least 20 points, the success rate was 90% in 51 hips in 51 patients at an average followup of 7 years. Segmental defects involving between 30% and 50% of the acetabulum are treated by minor column allografts (shelf graft), and a cemented or an uncemented cup. In 29 hips in 28 patients with an average followup of 7 years the success rate was 86%. Segmental defects involving more than 50% of the acetabulum are treated by major column allografts. These grafts are fixed by cancellous screws and protected by a reconstruction ring that extends from ilium to ischium. In 33 hips in 32 patients with an average followup of 7 years, the success rate was 76%.

Economic evaluations in the hip arthroplasty literature: lessons to be learned

Readers are increasingly encountering articles dealing with health economic evaluations that compare various surgical strategies, leaving orthopaedists with the challenge of determining which program is cost-efficient and truly pertains to their setting. This study carries out a systematic review of the literature to appraise the quality, quantity, and type of economic evaluation as it pertains to the hip arthroplasty literature. To identify all relevant articles, we conducted a comprehensive computerized bibliographic search of Medline from 1966 to 1996. This search produced 1,611 abstracts that were screened. Studies that were incorporated met the following inclusion criteria: i) formal economic analysis, ii) an intervention specific to hip arthroplasty, and iii) the perspective of the study was evident (ie, patient, provider, society). These studies were appraised with regards to methodologic soundness based on 8 established economic principles. Only 68 articles from the 138 retrieved met the study criteria. Only 2 of the 68 articles met all 8 criteria of a comprehensive economic evaluation. The hip arthroplasty literature is deficient in methodologically sound economic evaluations. Several guidelines are introduced to aid orthopaedists in appraising the various economic studies, and recommendations are made to improve the quality of these studies in the orthopaedic literature. We suggest that the generation of such information should rank high on the priority list of the orthopaedic profession, granting agencies, and governments.

The use of structural allografts for treating periprosthetic fractures about the hip and knee

When a periprosthetic fracture about the knee or hip is associated with segmental bone loss and a loose implant, a structural allograft may be indicated. The implant is cemented into the allograft but not into the host. The host graft junction is stabilized by the long stem of the implant and a step-cut osteotomy. The junction can be further reinforced by cortical strut allograft and residual host bone with soft tissues still attached to enhance union. Once the host bone unites to the allograft, the reconstruction is stabilized.

Evaluation of the allograft-prosthesis composite technique for proximal femoral reconstruction after resection of a primary bone tumour

OBJECTIVE

To evaluate clinical and functional outcomes resulting from the allograft-composite technique used for proximal femoral osteoarticular reconstruction in patients who had limb salvage surgery for primary bone tumours.

DESIGN

A retrospective review of a prospectively gathered database to provide a descriptive study.

SETTING

A tertiary care musculoskeletal oncology unit in a university hospital.

PATIENTS AND INTERVENTIONS

Patients treated between 1987 and 1993 were eligible for inclusion in this study if they met the following criteria: they were treated surgically for a primary malignant bone tumour; and a proximal femoral allograft-implant composite technique was used for the reconstruction.

MAIN OUTCOME MEASURES

Major postoperative complications with emphasis on mechanical complications in the reconstructive composite implant. Functional outcome in a subset of patients using the 1987 and 1994 versions of the Musculoskeletal Tumor Society instrument, the Short-Form-36 and the Toronto Extremity Salvage Score.

RESULTS

There were 5 mechanical and 2 infectious complications requiring surgical intervention. Functional scores were generally low.

CONCLUSIONS

Our results suggest that the perceived benefits of the composite technique may accrue only to a few patients, partly owing to the risk of mechanical complications. Although these can be reduced by avoiding the use of cement in the host femur, the generally poor functional outcomes suggest that this technique needs to be studied further in this group of patients and compared with other reconstructive techniques, particularly the prosthetic implant.

Proximal femoral allografts for reconstruction of bone stock in revision arthroplasty of the hip

Full circumferential bone loss of the proximal femur can be managed by segmental allografts. The use of these grafts is indicated for uncontained defects longer than five cm in length. The femoral implant is cemented into the allograft but not into the host. The allograft host junction is stabilized by a step cut or oblique osteotomy and autografted with residual host femur. The results at five and nine years support this kind of reconstruction as a good alternative for this difficult problem.

Fresh osteochondral allografts for post-traumatic osteochondral defects of the knee

We used fresh small-fragment osteochondral allografts to reconstruct post-traumatic osteochondral defects in 126 knees of 123 patients with a mean age of 35 years. At a mean follow-up of 7.5 years (2 to 20), 108 knees were rated as successful (85%) and 18 had failed (15%). The factors related to failure included age over 50 years (p = 0.008), bipolar defects (p < 0.05), malaligned knees with overstressing of the grafts, and workers' compensation cases (p < 0.04). Collapse of the graft by more than 3 mm and of the joint space of more than 50% were seen more frequently in radiographs of failed grafts. Our encouraging clinical results for fresh small-fragment osteochondral allografts show that they are indicated for unipolar post-traumatic osteochondral defects of the knee in young active patients.

Allograft reconstruction of the acetabulum after resection of stage-IIB sarcoma. Intermediate-term results

Seventeen consecutive patients were managed with an allograft reconstruction of the pelvis (including the acetabulum) following resection of a stage-IIB bone sarcoma during a twelve-year period. The initial diagnosis was chondrosarcoma in nine patients, osteosarcoma in six, Ewing sarcoma in one, and leiomyosarcoma in one. All patients who had osteosarcoma or Ewing sarcoma received chemotherapy preoperatively and postoperatively. Fifteen patients were managed with an allograft-total hip prosthesis composite. Two patients initially were managed with an osteoarticular allograft without a prosthesis, but one had a subsequent revision to an allograft-implant composite. Four patients died with an intact allograft reconstruction. Eight patients survived with an intact allograft reconstruction, and they were followed for at least four years (mean, seven years; maximum, fourteen years). All but one was able to walk in the community with one or two canes at the time of the latest follow-up. There was a high rate of local recurrence, which occurred in three of the seventeen patients, and of infection, which developed in two patients. The five patients had a subsequent hindquarter amputation or removal of the allograft. The mean functional score (and standard deviation), according to the rating system of the Musculoskeletal Tumor Society, was 65 +/- 21.16 per cent (median, 70 per cent; range, 13 to 87 per cent) for the thirteen patients who were thus evaluated. Preservation of the limb and reconstruction with an allograft may be considered as an alternative to hindquarter amputation in carefully selected patients who have a bone sarcoma involving the acetabulum. However, patients who have a high-grade bone sarcoma must be warned that there is a substantial risk of local recurrence or infection. In the present series, more than half of the patients either died or had failure of the reconstruction.

FRESH OSTEOCHONDRAL ALLOGRAFTS FOR POST-TRAUMATIC OSTEOCHONDRAL DEFECTS OF THE KNEE

We used fresh small-fragment osteochondral allografts to reconstruct post-traumatic osteochondral defects in 126 knees of 123 patients with a mean age of 35 years. At a mean follow-up of 7.5 years (2 to 20), 108 knees were rated as successful (85%) and 18 had failed (15%).

The factors related to failure included age over 50 years (p = 0.008), bipolar defects (p < 0.05), malaligned knees with overstressing of the grafts, and workers’ compensation cases (p < 0.04). Collapse of the graft by more than 3 mm and of the joint space of more than 50% were seen more frequently in radiographs of failed grafts.

Our encouraging clinical results for fresh small-fragment osteochondral allografts show that they are indicated for unipolar post-traumatic osteochondral defects of the knee in young active patients.

The flying buttress acetabular bone-graft

Primary total hip arthroplasty is often required in the end-stage osteoarthritic hip secondary to hip dysplasia. At the time of surgery, a decision is made whether to bone-graft the dysplastic acetabulum to accommodate the acetabular component. A technique is described to augment the acetabular bone stock by adding a flying buttress autograft to the structural shelf graft.