Capsular replacement with synthetic mesh: effectiveness in preventing postoperative dislocation after wide resection of proximal femoral tumors and prosthetic reconstruction

Using mesh in capsule anatomical reconstruction to enhance the stability of high-dislocation-risk hip arthroplasty: a randomized controlled trial

BACKGROUND

Dislocation is a common complication after total hip arthroplasty (THA). This study aimed to compare the outcomes of mesh reconstruction versus conventional capsular repair in maintaining capsular integrity and preventing dislocation after THA.

METHODS

This was a prospective, randomized controlled study of consecutive patients. A total of 124 high-dislocation-risk THAs were identified and randomized into two groups, one using mesh reconstruction and the other using the conventional capsular repair method. Perioperative data and radiological data were collected. Patients were followed up regularly. The main indices were the capsular integrity assessed by magnetic resonance imaging (MRI) and hip dislocation rate. The secondary indices included the Harris hip score (HHS), complications, and satisfaction.

RESULTS

A total of 106 patients completed the follow-up and the average follow-up times were 19 ± 3.1 and 18 ± 3.3 months. The operation time of the mesh group was longer than that of the conventional group (P < 0.001). There were minor differences in acetabular anteversion and abduction angle, and the other data showed no differences. MRI results indicated that the success rate of capsular repair was higher in the mesh group (50 hips, 98%) than in the conventional group (37 hips, 67%) (P < 0.001), and the others failed the repair. Three dislocations occurred in the conventional group, while none occurred in the mesh group. The preoperative HHS (30 points) and postoperative HHS (82 points) of the mesh group were similar to those (35 points, 83 points) of the conventional group (P = 0.164, P = 0.328). Satisfaction had no difference (P = 0.532).

CONCLUSIONS

Compared to conventional repair, mesh reconstruction can effectively maintain capsular integrity and decrease dislocation risk after THA without increasing complications.

LEVEL OF EVIDENCE

Therapeutic study, Level IA.

Outcomes After Abductor Reattachment to Proximal Femur Endoprosthesis After Tumor Resection

INTRODUCTION

Resection of the proximal femur raises several challenges including restoration of the abductor mechanism. Few evaluated the outcomes of different techniques of abductor fixation to the proximal femur endoprosthesis.

METHODS

A retrospective review of patients who underwent proximal femoral arthroplasty with a minimum follow-up of 12 months was conducted. Patients were divided into two groups: (1) those with preserved greater trochanter (GT) reattached to the implant and (2) those with direct abductor muscle reattachment. Both groups were compared for surgical and functional outcomes. Group 1 patients were subdivided into those who received GT reinsertion using grip and cables and those reattached using sutures.

RESULTS

Fifty-three patients were included with a mean follow-up of 49 months. There were 22 patients with reinserted GT and 31 patients with soft-tissue repair. The endoprosthesis revision rate was comparable between groups (P = 0.27); however, the incidence of dislocations was higher in group 2 (0/22 versus 6/31; P = 0.035). Trendelenburg gait (77% versus 74%), use of walking aids (68% versus 81%), and abductor muscle strength were comparable between both groups (P > 0.05). In group 1, 15 patients had GT reinsertion with grip and cables. Of those, five patients (33%) had cable rupture within 13 months of follow-up. GT displacement reached 12 mm at 12 months of follow-up in patients with grip and cables compared with 26 mm in patients with GT suture reinsertion (P < 0.05).

DISCUSSION

Although GT preservation did not improve functional outcomes, it was associated with a lower dislocation rate despite frequent cable failure. Less displacement was observed when GT reattachment used grip and cables.

Gluteus maximus transfer and mass graft (Capsulorraphy) in recurrent hip dislocation with the history of total hip replacement: A case series

•

Post THR dislocation has been a significant complication.

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Four patients operated by soft tissue procedure of gluteus maximus transfer as an abductor replacement and along with capsule augmentation using synthetic mesh as a synthetic capsule to strengthen and provide more stability.

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The use of mesh in soft tissue procedures, such as capsulorraphy, with the addition gluteus maximus transfer may assist to prevent (re)dislocations of the hip.

Introduction

Post THR dislocation has been a significant complication that interferes with the patient’s life. Detection of risk factors, careful planning, proper operative procedures, and patient education is essential to prevent the incidence of dislocation. Several operative measures have been studied to achieve this, including the use of mesh for soft tissue procedures and capsulorraphy.

Case Presentation

A total of four patients is included in this case series. Two had a history of trauma that contributes to the necessity of the procedure while the other two had degenerative joint issues. All were operated by soft tissue procedure of gluteus maximus transfer as an abductor replacement and along with capsule augmentation using synthetic mesh as a synthetic capsule to strengthen and provide more stability.

Discussion

The abductor strength from this gluteus maximus procedure is sufficient to stabilize the pelvis and prevent pelvic sag. The primary material of the mesh should produce inflammatory reaction so that a fibro capsular structure is formed surrounding the hip joint to add stability.

Conclusion

The use of mesh in soft tissue procedures, such as capsulorraphy, with the addition gluteus maximus transfer may assist to prevent (re)dislocations of the hip. However, further study should be conducted to validate the routine use of mesh and gluteus maximus transfer to prevent dislocation after the procedure.

Capsular Reconstruction of the Hip Using Modified Kite Technique: A Technical Guide for Efficient Graft Management and Fixation

Preserving capsular integrity has become an important principle of hip preservation surgery given the increasingly recognized deleterious effects of instability in cases of capsular insufficiency. When capsular tissue is deficient, capsular reconstruction may be indicated to restore function of the iliofemoral ligament and improve hip biomechanics. To date, few studies have presented technical guidance on performing arthroscopic capsular reconstruction of the hip. In this Technical Note, we introduce a modified kite technique for arthroscopic entry, control, and fixation of a capsular reconstruction graft. Similar to flying a kite with multiple fly lines, and to the previously described kite technique for hip labral reconstruction, the principles of this method are founded on the belief that control sutures within a pulley system facilitate safe and efficient graft management during capsular reconstruction procedures.

Outcomes of major musculoskeletal oncological reconstructions using prolene mesh-a retrospective analysis from a tertiary referral centre

BACKGROUND

Adequate reconstruction of the soft tissue defect following resection of bone tumors is challenging. Prolene mesh, despite being a useful tool, is not widely used due to the fear of deep infection. The aim of this study was to evaluate the functional outcome and complications of using a Prolene mesh in oncological reconstructions.

METHODS

A retrospective study was conducted in bone tumor patients with soft tissue reconstruction using Prolene mesh between January 2017 and June 2019. Functional evaluation was done using MSTS 93 score. Complications were recorded and were classified as mechanical (dislocation and extension lag) or biological failure (wound problems and deep infection). Comparison was performed between groups with and without biological failure to identify predictive variables.

RESULTS

Of 116 patients, 68 were males and 48 were females, with median age of 22.5 years. Thirty nine patients had tumors of proximal tibia, 23 of proximal femur, 25 of proximal humerus, 24 of pelvis, and five tumors at other sites. Approximately two-thirds (62.9%) of our patients underwent endoprosthetic reconstruction while the rest underwent either biological or cement spacer reconstructions. Excellent or good functional outcomes were reported in 98.3% patients as per MSTS 93 scoring. Complications were noted in 22 patients (18.9%), of which 16 had biological failure, with four patients requiring debridement and mesh removal. Dislocation of prosthesis occurred in 2 patients of proximal femur replacement. Overall re-surgery rate was 5.1% (6 patients). There was no statistically significant difference between the groups with or without biological failure with respect to demographics, site of tumor, type of procedure, blood loss, duration of surgery and history of chemotherapy.

CONCLUSION

Prolene mesh is a useful tool to reconstruct the soft tissue defects following bone tumor resections. It is readily available, reliable and provides reproducible results, with no added risk of wound complications.

The Patient With Chronic Total Hip Arthroplasty Dislocations: A Case Series of Five Patients Who Underwent Revision THA Using Polypropylene Mesh for Capsular Reconstruction

We report a case series of 5 patients who underwent revision total hip arthroplasty (THA) using a polypropylene mesh for capsular reconstruction for chronic THA instability. The average follow-up is 16.6 months (range, 9-20 months). There were no postoperative dislocations in our series. Three patients had previous infections with two-stage revisions before final revision surgery and were infection free at their most recent follow-up. One patient developed a prosthetic joint infection 2 months postoperatively. The use of a polypropylene mesh appears to be another tool that surgeons can use when dealing with the difficult dilemma on how to treat the patient with chronic THA instability and severe abductor and capsular tissue loss.

En-Bloc Resection of Metastases of the Proximal Femur and Reconstruction by Modular Arthroplasty is Not Only Justified in Patients with a Curative Treatment Option-An Observational Study of a Consecutive Series of 45 Patients

Background: There is little conformity regarding the surgical treatment of metastasis of the proximal femur, especially in palliative patients with limited life expectancy. Patients and Methods: En-bloc resection of secondary bone malignancies of the proximal femur and reconstruction by modular arthroplasty was performed in a consecutive series of 45 patients. The mean follow-up period was 16.4 months (0.6–74.7). Results: The survival rate of all patients was 6.6% (95% CI: 0–14.9) at 74.7 months. There was no significant difference in patients with a solitary or disseminated disease at index operation (log-rank p = 0.1214). Recurrent dislocation was the most frequent local complication (n = 6) necessitating an open reduction in four cases. The use of a Trevira tube showed a higher risk of dislocation compared to the simple bonding of remaining soft tissue (6 out of 28 vs. 0 out of 17; Fisher test: p = 0.0463). The worst-case survival rate with the removal of the arthroplasty for any cause and/or loss to follow-up was 80.0% (95% CI: 44.9–100) at 74.7 months (n = 1 due to low-grade infection). Conclusions: En-bloc resection of metastases and reconstruction by modular arthroplasty is reliable even in patients with very limited life expectancy. Local complications due to tumor growth or instability after intralesional surgery could be managed successfully but recurrent dislocation as the most frequent complication has to be taken into account. The simple bonding of remaining soft tissue around the prosthesis without the use of an attachment tube may reduce the dislocation rate and reoperation risk.

Cemented Proximal Femoral Replacement for the Management of Non-Neoplastic Conditions: A Versatile Implant but Not Without Its Risks

BACKGROUND

The demand for revision arthroplasty continues to grow. Proximal femoral bone loss poses a significant challenge to surgeons and proximal femoral replacements (PFRs) are one option to address this problem. The aim of our study is to assess the reoperation, complication, and mortality rates following PFR for treatment of non-neoplastic conditions.

METHODS

A retrospective observational study was conducted of a consecutive group of patients treated with a PFR for non-neoplastic conditions between 2010 and 2018. Mortality was confirmed using the Irish national death events publication service.

RESULTS

Over the 8-year study period, 79 PFRs in 78 patients were performed. Mean age of patients was 78.3 years (standard deviation 11.9), of which 37.2% were male. Periprosthetic fracture was the most common indication for PFR (63.3%). The 30-day mortality rate was 7.6% (6 patients), of which bone cement implantation syndrome occurred in 4 patients. One-year mortality was 12.7%. Complications occurred in 22.8%.

CONCLUSION

A cemented PFR is a versatile prosthesis in the armamentarium of a revision arthroplasty surgeon that allows immediate full weight-bearing. However, it may appropriately be considered a last resort procedure that poses specific risks that must be explained to patients and family. We present the short-term outcomes on one of the largest series of PFR to date.

Radial Neck-to-Humerus Transposition for Elbow Reconstruction Following Oncologic Resection of the Proximal Ulna: A Report of Two Cases

CASE

Two young adult (aged 25 and 21 years) patients presented with sarcomas of the proximal ulna. To achieve an oncological margin, the proximal ulna required resection. Owing to the complex biomechanics of the elbow joint, reconstructive options are limited and have a high complication rate. The elbow was reconstructed with a transposition of the radial neck to the trochlea of the humerus in both patients. At over 2 years of follow-up, both patients have a stable and functional elbow.

CONCLUSIONS

Transposition of the radial neck to the trochlea of the humerus provides a biological reconstruction in this complex problem.

How Often Do Acetabular Erosions Occur After Bipolar Hip Endoprostheses in Patients With Malignant Tumors and Are Erosions Associated With Outcomes Scores?

BACKGROUND

Bipolar endoprosthetic replacement is an option for reconstruction of the proximal femur to restore a functional extremity and salvage the limb. However, because these patients are young, there is a theoretical risk for long-term degenerative changes of the acetabulum. Currently, there is a paucity of data concerning the proportion of patients who experience degenerative acetabulum changes after reconstruction and whether these changes are associated with Musculoskeletal Tumor Society (MSTS) scores.

QUESTIONS/PURPOSES

(1) What proportion of patients develop acetabular cartilage degeneration after bipolar hemiarthroplasty for malignant tumor-related reconstructions? (2) What is the survivorship free from revision for acetabular wear, erosions, or progressive arthritis? (3) Is there an association between the presence of acetabular erosions and lower MSTS scores?

METHODS

Between 2000 and 2015, 148 patients underwent endoprosthetic reconstruction of the proximal femur with a bipolar hemiarthroplasty for a malignant tumor and were potentially eligible for this retrospective study. Minimum followup was 1 year except for those who died or were revised earlier; of the 148, no patients were lost to followup before that time who were not known to have died; mean followup on the remainder was 79 months (range, 12-220 months), and the mean time to death after surgery for those who died was 28 months (range, 0-196 months). Over the course of the study, 93 (63%) patients died. The mean (± SD) patient age was 57 ± 17 years, and 55% (81 of 148) of the patients were men. We used magnification-corrected supine AP plain radiographs of the hip to evaluate degenerative acetabulum changes, and we used the 1993 MSTS score to assess function through chart review and a longitudinally maintained institutional database. We used a competing-risks survivorship estimator rather than Kaplan-Meier because of the high proportion of patients who had died during the surveillance period.

RESULTS

Nineteen patients (13%) developed cartilage erosion > 2 mm in the acetabulum, with two also developing protrusio after proximal femoral replacement with a bipolar endoprosthesis. Three additional patients also developed signs of protrusio. The mean acetabular wear after bipolar replacement was 1.2 mm. Patients with longer followup (p = 0.001) were at higher risk for developing acetabular wear. Six patients underwent conversion to THA to treat hip pain. At 10 years the cumulative incidence for conversion to THA for acetabular wear is 5% (95% confidence interval [CI], 0%-11%), whereas the cumulative incidence of death was 70% (95% CI, 61%-79%). There was no difference in mean MSTS scores between patients who developed > 2 mm of acetabular erosion (65% ± 25%) and those who did not (67% ± 20%; p = 0.77).

CONCLUSIONS

Wear was uncommon among patients with malignant hip tumors treated with bipolar endoprostheses, but the followup here was short, and some patients indeed developed wear and underwent wear-related revisions to THA. Patients expected to survive more than a few years should have periodic radiographic surveillance and should be followed for a longer period to get a better sense for whether the problem worsens with time, as we expect it may, among patients who survive for longer periods.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Outcomes of Endoprosthetic Replacement for Salvage of Failed Fixation of Malignant Pathologic Proximal Femur Fractures

BACKGROUND

Internal fixation is often used to treat pathologic proximal femur fractures. However, nonunion and/or tumor progression may lead to hardware failure. In such cases, endoprosthetic replacement may be considered. The purpose of this study is to analyze the outcome of patients undergoing conversion to an endoprosthetic replacement following failed fixation of a pathological proximal femur fracture.

METHODS

We identified 26 patients who underwent conversion hip arthroplasty for salvage of failed fixation of a pathologic proximal femur fracture between 2000 and 2016. Previous surgical hardware included femoral nail (n = 18), dynamic hip screw (n = 5), proximal femoral locking plate (n = 1), blade plate (n = 1), and cannulated screws (n = 1). Twenty-one patients had metastatic disease, 4 myeloma, and 1 lymphoma. All received adjuvant or neoadjuvant radiotherapy at a mean dose of 30 Gy.

RESULTS

There were 15 males and 11 females with mean age 63 ± 11 years. Patients underwent conversion arthroplasty at a mean of 13 ± 12 months after initial fixation. At final follow-up, 19 patients had died, with 5-year overall survival of 35%. Conversion to arthroplasty was performed due to disease progression (n = 12), hardware failure (n = 8), and nonunion (n = 6). Eight hips required reoperation, most commonly for infection (n = 4). At last follow-up, the Harris Hip Scores (P < .001) and Musculoskeletal Tumor Society Scores (P < .001) significantly improved from a mean of 24 and 14 preoperatively to 68 and 59 postoperatively, respectively.

CONCLUSION

Conversion hip arthroplasty reliably provides improved quality of life and immediate weight bearing, making it an effective treatment for salvage of failed fixation of pathologic proximal femur fractures.

Use of an Artificial Ligament Decreases Hip Dislocation and Improves Limb Function After Total Femoral Prosthetic Replacement Following Femoral Tumor Resection

BACKGROUND

Hip dislocation is a major complication of total femoral prosthetic reconstruction (TFR) after femoral tumor resection. Hip dislocation can occur because of inadequate functional abductor musculature, inadequate hip capsule repair, or a long lever arm after total femur replacement. To eliminate the negative effects of these factors on the risk of hip dislocation, the use of artificial ligaments may help to increase the stability of the hip joint. We aimed to determine whether application of an artificial ligament would improve limb function and active range of movement (ROM) after TFR.

METHODS

Fifty-eight patients who underwent femoral tumor resection and TFR were included. A band-shaped artificial ligament was wrapped spirally around the proximal site of the total femur prosthesis for periacetabular soft tissue reconstruction in 12 patients. The other 46 patients did not consent to receiving the artificial ligament. Complications including hip dislocation and infection, limb function, and active hip ROM were compared between patients who did and did not receive the artificial ligament.

RESULTS

The hip dislocation rate was lower in the patients who received the artificial ligament. The risk of deep infection did not differ between groups. The group that received the ligament also achieved better limb function and active ROM on flexion and abduction.

CONCLUSION

Patients treated with total femur resection and endoprosthetic replacement with an artificial ligament for periacetabular soft tissue reconstruction had a more stable hip joint, better limb function, and greater active hip ROM than did patients who did not receive an artificial ligament.

The stability of the hip after the use of a proximal femoral endoprosthesis for oncological indications: analysis of variables relating to the patient and the surgical technique

AIMS

Instability of the hip is the most common mode of failure after reconstruction with a proximal femoral arthroplasty (PFA) using an endoprosthesis after excision of a tumour. Small studies report improved stability with capsular repair of the hip and other techniques, but these have not been investigated in a large series of patients. The aim of this study was to evaluate variables associated with the patient and the operation that affect post-operative stability. We hypothesised an association between capsular repair and stability.

PATIENTS AND METHODS

In a retrospective cohort study, we identified 527 adult patients who were treated with a PFA for tumours. Our data included demographics, the pathological diagnosis, the amount of resection of the abductor muscles, the techniques of reconstruction and the characteristics of the implant. We used regression analysis to compare patients with and without post-operative instability.

RESULTS

A total of 20 patients out of 527 (4%) had instability which presented at a mean of 35 days (3 to 131) post-operatively. Capsular repair was not associated with a reduced rate of instability. Bivariate analysis showed that a posterolateral surgical approach (odds ratio (OR) 0.11, 95% confidence interval (CI) 0.02 to 0.86) and the type of implant (p = 0.046) had a significant association with reduced instability; age > 60 years predicted instability (OR 3.17, 95% CI 1.00 to 9.98). Multivariate analysis showed age > 60 years (OR 5.09, 95% CI 1.23 to 21.07), female gender (OR 1.73, 95% CI 1.04 to 2.89), a malignant primary bone tumour (OR 2.04, 95% CI 1.06 to 3.95), and benign condition (OR 5.56, 95% CI 1.35 to 22.90), but not metastatic disease or soft-tissue tumours, predicted instability, while a posterolateral approach (OR 0.09, 95% CI 0.01 to 0.53) was protective against instability. No instability occurred when a synthetic graft was used in 70 patients.

CONCLUSION

Stability of the hip after PFA is influenced by variables associated with the patient, the pathology, the surgical technique and the implant. We did not find an association between capsular repair and improved stability. Extension of the tumour often dictates surgical technique; however, our results indicate that PFA using a posterolateral approach with a hemiarthroplasty and synthetic augment for soft-tissue repair confers the lowest risk of instability. Patients who are elderly, female, or with a primary benign or malignant bone tumour should be counselled about an increased risk of instability. Cite this article: Bone Joint J 2017;99-B:531-7.

The Stress-Strain Data of the Hip Capsule Ligaments Are Gender and Side Independent Suggesting a Smaller Contribution to Passive Stiffness

Background

The ligaments in coherence with the capsule of the hip joint are known to contribute to hip stability. Nevertheless, the contribution of the mechanical properties of the ligaments and gender- or side-specific differences are still not completely clear. To date, comparisons of the hip capsule ligaments to other tissues stabilizing the pelvis and hip joint, e.g. the iliotibial tract, were not performed.

Materials & Methods

Hip capsule ligaments were obtained from 17 human cadavers (9 females, 7 males, 13 left and 8 right sides, mean age 83.65 ± 10.54 years). 18 iliofemoral, 9 ischiofemoral and 17 pubofemoral ligaments were prepared. Uniaxial stress-strain properties were obtained from the load-deformation curves before the secant elastic modulus was computed. Strain, elastic modulus and cross sections were compared.

Results

Strain and elastic modulus revealed no significant differences between the iliofemoral (strain 129.8 ± 11.1%, elastic modulus 48.8 ± 21.4 N/mm²), ischiofemoral (strain 128.7 ± 13.7%, elastic modulus 37.5 ± 20.4 N/mm²) and pubofemoral (strain 133.2 ± 23.7%, elastic modulus 49.0 ± 32.1 N/mm²) ligaments. The iliofemoral ligament (53.5 ± 15.1 mm²) yielded a significantly higher cross section compared to the ischiofemoral (19.2 ± 13.2 mm²) and pubofemoral (15.2 ± 7.2 mm²) ligament. No significant gender- or side-specific differences were determined. A comparison to the published data on the iliotibial tract revealed lower elasticity and less variation in the ligaments of the hip joint.

Conclusion

Comparison of the mechanical data of the hip joint ligaments indicates that their role may likely exceed a function as a mechanical stabilizer. Uniaxial testing of interwoven collagen fibers might lead to a misinterpretation of the mechanical properties of the hip capsule ligaments in the given setup, concealing its uniaxial properties. This underlines the need for a polyaxial test setup using fresh and non-embalmed tissues.

Late complications and long-term outcomes following aseptic revision of a hip arthroplasty performed for oncological resection

PURPOSE

In order to achieve an oncological margin during limb salvage surgery for tumours around the hip, part or the entire hip joint is frequently sacrificed. Hip arthroplasty restores a functional extremity and achieves limb salvage. Currently there is a paucity of data concerning the late complications, long-term survival, and the risks of re-revision following aseptic revision of a total hip arthroplasty (THA) performed following an oncological resection.

METHODS

We identified 78 patients who underwent aseptic revision of a THA which was performed for an oncological process involving the hip from 1972 to 2006. All patients had a minimum 5 years of follow-up with a mean of 13 years. Outcomes were compared to 1,378 patients undergoing aseptic revision of a THA that was performed for a diagnosis of osteoarthritis.

RESULTS

The mean 5-, 10-, 15-, and 20-year re-revision-free survival for an oncologic process of the hip was 100%, 85%, 69%, and 57%. Within this cohort, younger patients were at an increased risk of revision surgery. There was no difference in survivorship of the revision implant at any of the aforementioned time points between the oncologic and osteoarthritis cohorts. Patients with an oncologic diagnosis had a higher rate of dislocations, component wear, and loosening compared to the osteoarthritis group.

CONCLUSION

Late complications following revision surgery of THA performed for an oncologic resection are common. The results of this study provide information for counselling patients on implant survivorship and complications following aseptic revision THA after index surgery for an oncologic indication.

New endoprosthesis suspension method with polypropylene monofilament knitted mesh after resection of bone tumors in proximal humerus

BACKGROUND

Endoprosthetic reconstruction of the proximal humerus is one of the standard procedures after resection of tumors of the proximal humerus and has been considered a reliable method to reconstruct the proximal humerus in recent reports. However, instability of the shoulder joint caused by loss of the rotator cuff and deltoid muscle function is often observed after such an endoprosthetic reconstruction.

METHODS

We performed the endoprosthesis suspension method with polypropylene monofilament knitted mesh. This suspension method, by which the endoprosthesis is suspended from the bone structure, was used after resection of tumors in 9 patients. We assessed postoperative stability of the shoulder joint by comparing these patients with 12 patients who underwent the conventional surgical technique, by which the mesh-wrapped endoprosthesis is attached only to soft tissue.

RESULTS

In radiographic and physical evaluation, 4 of the 12 patients in the soft tissue reconstruction group showed shoulder joint instability. No patient in the suspension method group showed subluxation of the humeral prosthesis. The mean shoulder flexion was 35° and 65° and the mean shoulder abduction was 40° and 40° for the soft tissue reconstruction group and the suspension method group, respectively.

DISCUSSION

Shoulder joint subluxation sometimes occurs because of elongation of the attached soft tissue in the conventional reconstruction with mesh, whereas no shoulder joint subluxation occurs after endoprosthetic reconstruction in the suspension method because the bone structure has no leeway for elongation. Excellent stability of our new method enables exercise of the surgical shoulder at an early stage, leading to improved range of shoulder joint motion.

Incidence and management of hip dislocation in tumour patients with a modular prosthesis of the proximal femur

PURPOSE

Little data is available about the incidence and especially the management of hip dislocation following the implantation of modular tumor prostheses of the proximal femur. In this retrospective single-centre study we assessed the incidence of hip dislocation following implantation of a proximal femoral modular prosthesis as well as the success of the subsequent surgical or non-surgical treatment in tumor patients.

METHODS

Between 1982 and 2008, 166 tumor patients received a modular prosthesis of the proximal femur at our institution. The average age at the time of surgery was 50 ± 20 years (range, six to 84 years). An additional pelvic reconstruction was done in 14 patients. An artificial band for soft tissue reconstruction of the hip was used in 19 patients. The average time of follow-up was 46 ± 64 months (range, one to 277 months).

RESULTS

The overall dislocation rate after proximal femoral replacement was 13% after a mean time of seven ± eight months (range, 0.3-33 months) after surgery. Between 1982 and 1986 the dislocation rate was 33% and declined to 9% in subsequent years (1987-2008). Patients who had received an additional pelvic reconstruction had a three fold higher dislocation rate (p <0.05). Patients with closed reduction had a 58% (eight of 12) re-dislocation rate compared to 11% (one of nine) for open reduction (p = 0.0357).

CONCLUSIONS

Dislocation of a modular prosthesis of the proximal femur is a common complication, especially in cases with additional pelvic resection with extensive bone and soft-tissue defects. Open surgical management may be more effective in preventing re-dislocation than closed reduction and bracing alone.

Arthroscopic capsulotomy, capsular repair, and capsular plication of the hip: relation to atraumatic instability

PURPOSE

The purpose of this systematic review was to critically evaluate the available literature exploring the role of the hip joint capsule in the normal state (stable) and pathologic states (instability or stiffness). Furthermore, we examined the various ways that arthroscopic hip surgeons address the capsule intraoperatively: (1) capsulotomy or capsulectomy without closure, (2) capsulotomy with closure, and (3) capsular plication.

METHODS

Two independent reviewers (B.D.G. and B.G.D.) performed a systematic review of the literature using PubMed and the reference lists of related articles by means of defined search terms. Relevant studies were included if these criteria were met: (1) written in English, (2) Levels of Evidence I to V, (3) focus on capsule and its role in hip stability, and (4) human studies and reviews. Articles were excluded if they evaluated (1) total hip arthroplasty constructs using bony procedures or prosthetic revision, (2) developmental dysplasia of the hip where reorientation osteotomies were used, (3) syndromic instability, and (4) traumatic instability with associated bony injury.

RESULTS

By use of the search method described, 5,085 publications were reviewed, of which 47 met appropriate criteria for inclusion in this review. Within this selection group, there were multiple publications that specifically addressed more than 1 of the inclusion criteria. Relevant literature was organized into the following areas: (1) capsular anatomy, biomechanics, and physiology; (2) the role of the capsule in total hip arthroplasty stability; (3) the role of the capsule in native hip stability; and (4) atraumatic instability and capsulorrhaphy.

CONCLUSIONS

As the capsuloligamentous stabilizers of the hip continue to be studied, and their role defined, arthroscopic hip surgeons should become facile with arthroscopic repair or plication techniques to restore proper capsular integrity and tension when indicated.

LEVEL OF EVIDENCE

Level IV, systematic review.

Biomechanical concept and clinical outcome of dual mobility cups

Dual mobility cup systems in total hip arthroplasty consist of a metal back with a non-constrained liner, in which a constrained standard head articulates. While superior stability of such implants in comparison with standard total hip replacements is assumed, it is the purpose of this study to outline the biomechanical concept of dual mobility cups and to describe implant survival and dislocation rate based on the series published in the English-speaking and Francophone literature. A growing body of evidence indicates reduced dislocation rates in primary and revision total hip arthroplasty and in selected tumour cases. The limited availability of studies evaluating long-term implant survival and existing concerns with regard to increased wear rates and aseptic loosening, leads to the conclusion that such implants have to be used with prudence, particularly in standard primary hip arthroplasty and in young patients.

Patient-oriented functional results of total femoral endoprosthetic reconstruction following oncologic resection

BACKGROUND AND OBJECTIVES

Functional outcomes following oncologic total femoral endoprosthetic reconstruction (TFR) are lacking. We compared patient-oriented functional results of TFRs to proximal femur and distal femur reconstructions (PFR and DFR). We also compared function and complications with regard to knee and hip componentry.

METHODS

Fifty-four TFR patients were identified from three institutional prospective databases. Forty-one had fixed- and 13 had rotating-hinge knees, 37 hemiarthroplasty and 17 total hip arthroplasty componentry. Toronto Extremity Salvage Scores (TESS) for n = 27 were compared between groups and to cohorts of PFR (n = 31) and DFR (n = 85) patients using the Mann-Whitney U-test.

RESULTS

Follow-up averaged 4 years. Mechanical complications included five hip dislocations and one femoral malrotation. Four dislocations were in fixed-hinge implants, all in those lacking abductor reattachment. TESS averaged 69.3 ± 17.8, statistically decreased from DFR (P = 0.002) and PFR patients (P = 0.036). No significant differences were detected between patients in the fixed-hinge (n = 18) and rotating-hinge (n = 9) groups (P = 0.944), or total hip (n = 8) and hemiarthroplasty (n = 19) groups (P = 0.633).

CONCLUSIONS

TFR is reserved for extreme cases of limb salvage, portending a poor prognosis overall. Function reflects additive impairments from PFR and DFR. TFR outcomes differ little with rotating- or fixed-hinge, total hip or hemiarthroplasty implants.

Pasteurized autograft-prosthesis composite for proximal femoral reconstruction: an alternative to allograft composite

BACKGROUND

Allograft-prosthesis composite (APC) for proximal femur reconstruction have shown favorable longevity and functional outcome compared to endoprosthesis, owing to restoration of bone stock, load-sharing property, and biological attachment of abductors and iliopsoas tendons.

QUESTIONS/PURPOSES

This study examined whether a pasteurized-prosthesis composite (PPC) is comparable to APC regarding implant survival, functional outcome, and complication rates.

PATIENTS AND METHODS

We retrospectively reviewed 18 patients with proximal femur malignancy that underwent reconstruction with a cemented pasteurized autograft-prosthesis composite between 1993 and 2008. We evaluated implant survival (Kaplan-Meier), functional outcome (MSTS score), complications and secondary operations.

RESULTS

The estimated survival rate of the 18 composites was 86% at 5 and 10 years. Within a mean follow-up of 93 months (median 113, range 14-163) two composites (11%) were removed due to un-resolving infection. The mean MSTS functional score of surviving 16 composites was 80% (range 70-95). Non-union and stem loosening in host bone were identified in a single patient, while infection developed in two patients. THA conversion occurred in three composites due to secondary osteoarthritis in two, and subluxation in one case. Two of the six cases, with greater trochanter (GT) reconstruction, showed GT avulsion. No autograft was fractured.

CONCLUSIONS

Pasteurized autograft-prosthesis composite (PPC) of the proximal femur has comparable survival rate, functional outcome, and complication rates to allograft-prosthesis composite (APC), thereby offering an alternative reconstructive option for proximal femoral reconstruction.

Failure mode classification for tumor endoprostheses: retrospective review of five institutions and a literature review

BACKGROUND

Massive endoprostheses provide orthopaedic oncologists with many reconstructive options after tumor resection, although failure rates are high. Because the number of these procedures is limited, failure of these devices has not been studied or classified adequately. This investigation is a multicenter review of the use of segmental endoprostheses with a focus on the modes, frequency, and timing of failure.

METHODS

Retrospective reviews of the operative databases of five institutions identified 2174 skeletally mature patients who received a large endoprosthesis for tumor resection. Patients who had failure of the endoprosthesis were identified, and the etiology and timing of failure were noted. Similar failures were tabulated and classified on the basis of the risk of amputation and urgency of treatment. Statistical analysis was performed to identify dependent relationships among mode of failure, anatomic location, and failure timing. A literature review was performed, and similar analyses were done for these data.

RESULTS

Five hundred and thirty-four failures were identified. Five modes of failure were identified and classified: soft-tissue failures (Type 1), aseptic loosening (Type 2), structural failures (Type 3), infection (Type 4), and tumor progression (Type 5). The most common mode of failure in this series was infection; in the literature, it was aseptic loosening. Statistical dependence was found between anatomic location and mode of failure and between mode of failure and time to failure. Significant differences were found in the incidence of failure mode Types 1, 2, 3, and 4 when polyaxial and uniaxial joints were compared. Significant dependence was also found between failure mode and anatomic location in the literature data.

CONCLUSIONS

There are five primary modes of endoprosthetic failure, and their relative incidences are significantly different and dependent on anatomic location. Mode of failure and time to failure also show a significant dependence. Because of these relationships, cumulative reporting of segmental failures should be avoided because anatomy-specific trends will be missed. Endoprosthetic design improvements should address failure modes specific to the anatomic location.

Dual mobility design use in preventing total hip replacement dislocation following tumor resection

INTRODUCTION

Total hip replacement (THR) following hip tumor resection incurs a high risk of dislocation. We assessed the incidence of dislocation associated with use of a dual mobility cup,and the functional results achieved.

HYPOTHESIS

Use of a dual mobility cup would reduce the risk of THR instability following hip tumor resection.

MATERIAL AND METHODS

We analyzed dislocation rates in a retrospective series of 71 dual mobility cup THRs implanted following the resection of a tumor hip condition: 33 primary bone tumors and 38 bone metastases. The presenting pathology was diagnosed anatomically, and surgery classified in terms of adopted abductor system strategy. Functional results were assessed in terms of pain (analgesia on the World Health Organisation [WHO] scale), assisted walking and Musculoskeletal Tumor Society (MSTS) score.

RESULTS

An overall rate of 9.8% dislocation was observed, taking into account all etiologies and contexts together. More precisely, this rate resulted from a compound figure of 5.2% in bone metastasis and 15% in primitive bone tumor. Dislocation risk depended lesson etiology than on the surgical management of the abductor system, being 3.5% in the case of abductor conservation, 9.5% in the case of abductor sectioning/reinsertion, and 18%in case of gluteus medius muscle or nerve resection. Functional improvement was consistently observed, especially in bone metastasis. At the maximal follow-up, 32 patients were not using analgesics, six were taking WHO class III analgesics, 10 class II and 23 class I. Mean MSTS score was 68.1% +/- 23.5% in bone metastasis and 59.6% +/- 17.5% in primary bone tumor.Fourteen patients could walk without assistance, 33 with a single cane, 15 with two canes and eight with a walker; one patient had not been able to resume walking.

DISCUSSION

In these indications, dual mobility cups use lead to lower dislocation rates than those reported in the literature. It proved especially effective in the case of bone metastasis and consolidation surgery. In the case of primary bone tumor, it failed to prevent dislocation following acetabular resection, especially when involving the abductor muscles and/or abductor innervation, although it provided lower dislocation rates, comparable to those experienced with other techniques, when applied to limited resection.

LEVEL OF EVIDENCE

IV. Retrospective therapeutic study.

Proximal femur allograft-prosthesis with compression plates and a short stem

Proximal femur allograft-prosthesis composites (APCs) performed with compression plates and a short stem theoretically could minimize the resorption or nonunion that reportedly occurs with long stems bypassing the diaphyseal osteotomy. To confirm this theoretical consideration, we retrospectively reviewed 34 patients with 38 proximal femoral APCs using a short-cemented femoral stem and compression plates for diaphyseal osteotomy fixation. In 26 patients, the plate fixation extended over at least half the femoral stem and in 12, it did not. We reinserted the abductor mechanism with two techniques: in 10 cases the host trochanter was reattached to the APC, and in 28 the host tendons were sutured to the tendinous insertion of the allograft. The overall survival of the entire series was 72% at 5 years and 69% at 10 years. Eleven of the 38 (29%) APCs were removed: three for infection, one for local recurrence of tumor, and seven for fractures. Trendelenburg gait occurred in four of 21 patients with direct tendon-to-tendon suture of the abductor mechanism and in three of six patients with trochanteric osteotomy. The overall APC survival rate was greater in patients in whom the allograft was adequately protected with internal fixation than in patients in whom it was not.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Endoprosthetic and allograft-prosthetic composite reconstruction of the proximal femur for bone neoplasms

Reconstruction of the proximal femur after tumor resection can be achieved with either an endoprosthesis or an allograft-prosthetic composite. We compared the two modalities for complications, functional outcome, and construct survival. We retrospectively analyzed 52 patients with endoprostheses and 20 with allograft-prosthetic composite reconstructions between 1974 and 2002. Median followup was 146 months and 76 months, respectively. Both methods were associated with low rates of early complications. Infections occurred in two patients with endoprostheses and one patient with an allograft-prosthetic composite reconstruction. Aseptic loosening was the most common (10%) late complication for patients with endoprostheses. Nonunion was the most common (10%) complication for patients with allograft prosthetic composite reconstructions. All host-allograft junctions eventually healed after bone-grafting. The Musculo skeletal Tumor Society scores were similar for patients with endoprostheses (70%) and allograft-prosthetic composites (82%). The median hip abductor strength was greater for patients with allograft-prosthetic composite reconstructions (4.6 of 5) than for patients with endoprostheses (2.8 of 5). Kaplan-Meier survivorship of the implant was 86% for both groups at 10 years. The consistent restoration of abductor muscle strength combined with the low morbidity and high durability support the use of allograft-prosthetic composite reconstruction in patients with long life expectancy.

LEVEL OF EVIDENCE

Therapeutic study, Level IV (case series--no, or historical control group). See the Guidelines for Authors for a complete description of levels of evidence.

Outcome in two groups of patients with allograft-prosthetic reconstruction of pelvic tumor defects

To predict the outcomes obtained with allograft-implant composite reconstruction of pelvic defects after bone tumor resection better, a retrospective review of a prospectively collected database was done and two groups of patients were identified. These groups were compared with respect to oncologic and functional outcomes in this investigation. Group 1 included 21 patients with allograft total hip replacement reconstruction for pelvic bone tumors that required Type I and II or Type I, II, and III pelvic resections. Group 2 included five patients who required an acetabular allograft in combination with proximal femoral replacement for reconstruction of Type II pelvic resections done to treat proximal femoral bone sarcomas that invaded or surrounded the hip joint. Functional assessment was measured with three instruments (Toronto Extremity Salvage Score, Musculoskeletal Tumor Society 1987, and the Musculoskeletal Tumor Society 1993 scores). In Group 1, nine of 19 evaluable patients (two patients died in the immediate postoperative period) either retained the allograft until their death or were still alive at last followup with their allograft in place. An additional patient had revision surgery to an allograft-saddle composite that remains intact. The functional results in Group 1 were influenced heavily by the occurrence of deep infection. Nine of 19 evaluable patients developed infection, with seven patients requiring either removal of the graft (three patients) or hindquarter amputation (four patients). Two patients retained their infected allografts with long-term antibiotic suppression. In 10 Group 1 patients who did not develop infection, reasonable functional results were obtained. Group 2 patients had no infections and better functional results.

LEVEL OF EVIDENCE

Therapeutic study, Level IV-1 (case series). See the Guidelines for Authors for a complete description of levels of evidence.

Proximal femur reconstruction by an allograft prosthesis composite

Twenty-seven patients who had resection of the proximal femur for bone tumors and reconstruction with an allograft prosthesis composite are reported. In most of the patients, the prosthesis was a long-stem revision type, cemented in the allograft and uncemented in the femoral shaft. The abductor muscles and iliopsoas were sutured to the corresponding tendons on the allograft. Implant-related complications and functional results were evaluated and are reported. Twenty-two patients achieved a minimum followup of 36 months (range, 36-126 months; average, 58 months). The implant was removed in two patients (one for infection, one for intraoperative fracture of the allograft). One patient experienced nonunion, whereas in the remaining 24 patients, the allograft eventually united to the host bone. A frequent late complication (17 patients) was fracture of the greater trochanter of the allograft. In the whole series, only four new operations were done for implant-related complications. In 22 patients who could be evaluated, the functional evaluation according to the Musculoskeletal Tumor Society System was excellent in 16 (73%) patients, good in four (18%), and fair in two (9%). These results compare favorably with those of megaprostheses for tumor resection of the proximal femur, where a Trendelenburg gait almost always is present.

Recurrent dislocation after total hip arthroplasty: treatment with an Achilles tendon allograft

Surgical treatment of recurrent dislocation after total hip arthroplasty (THA) is challenging with often disappointing results. Among possible causes of dislocation, the influence of the static soft tissue restraint provided by the hip capsule is important, and restoration of its integrity and function is a major goal of treatment. We describe a new technique in which an Achilles tendon allograft is employed as a checkrein to limit hip internal rotation and to prevent posterior instability. Ten unstable THAs were treated using this technique, eliminating instability in 6. At an average follow-up of 3 years, Achilles tendon allograft augmentation has proved to be a useful adjunct for the treatment of recurrent posterior dislocation after THA in selected patients.

Instability after major tumor resection: prevention and treatment

Instability is a significant problem after resection of musculoskeletal tumors. In this article, the authors discuss the issue of instability after resections of the pelvis, the femur, and the proximal tibia. The options for reconstruction in each area are discussed along with a review of the literature and a description of the authors' preferred approach.