Cementless, modular, distally fixed stem in hip revision arthroplasty: a single-center study of 132 consecutive hips

Cementless primary or revision stem in revision hip arthroplasty for aseptic stem loosening with Paprosky type I/II femoral defect?

BACKGROUND

The use of primary or revision stem during revision total hip arthroplasty (THA) for aseptic stem loosening with Paprosky type I/II femoral defect remains controversial. The aim of this study was to compare the outcomes of patients who underwent revision THA with a primary or revision stem.

METHODS

We retrospectively reviewed 78 patients who received revision THA for aseptic stem loosening using primary (N = 28) or revision stems (N = 50). The bone defects were classified as Paprosky type I or II. The mean follow-up duration was 72.3 ± 34.7 months. The primary outcome domains included surgical complications and implant failures. The secondary outcome domains included medical complications, 30- and 90-day readmission, and Harris hip score (HHS).

RESULTS

The use of revision stem was associated with a higher incidence than primary stem of patient complications (60.0% vs. 32.1%, p = 0.018), including intraoperative femur fracture (28.0% vs. 7.1%, p = 0.029) and greater trochanter fracture (16.0% vs. 0%, p = 0.045). The implant survival rate was comparable between groups. HHS at the final follow-up was similar.

CONCLUSION

With a lower risk of surgical complications and a similar rate of mid-term implant survival, cementless primary stem appears superior to revision stem in revision THA for aseptic stem loosening with Paprosky type I/II femoral defect.

Medium Term Radiographic and Clinical Outcomes Using a Modular Tapered Hip Revision Implant

Background

The rate of revision hip arthroplasty surgery is rising. Surgeons must use implants with proven outcomes to help overcome the technical challenges faced during revision surgery. However, outcome studies using these implants are limited. The aim of this study is to investigate the radiographic and clinical outcomes of the Stryker Restoration stem, the most commonly used hip revision stem in the United Kingdom (UK).

Methods

A retrospective review of a single surgeon case series was performed. Immediate postoperative radiographs were analyzed for offset and leg length discrepancy. Radiographic evidence of subsidence was assessed using follow-up radiographs. Kaplan-Meier survival analysis was applied using explantation and reoperation as endpoints. Patient-reported outcomes were measured using the Oxford Hip Score and EQ-5D-5L.

Results

One hundred ninety-eight cases were identified. Mean follow-up duration was 51.8 months (range: 24-121). Stem survival during this period was 98%. Reoperation for any reason was 13%. Mean subsidence was 4.18 mm. Analysis of variance testing showed no difference in mean subsidence between revision indications. Mean offset and leg length discrepancies were measured at 4.5 mm and 4.3 mm, respectively. The mean Oxford Hip Score for participants was 27.6.

Conclusions

This series demonstrates excellent implant survival, with radiographic parameters for reconstruction and subsidence levels comparable to those in the existing literature. The tapered modular hip revision stem provides surgeons with the intraoperative flexibility to overcome some of the anatomical difficulties encountered during revision surgery; this is reflected in the radiographic and clinical outcomes of the cohort in this study.

Conversion total hip arthroplasty with a proximally modular, distal fixation reconstruction prosthesis following cephalomedullar nail failure

BACKGROUND

The goals of intertrochanteric hip fracture (IHF) treatment are stable fixation, early mobilisation and function restoration. If the attempt to reduce, stabilise and fracture healing utilising a femoral cephalomedullar nail (CMN) fails, options for subsequent attempts are limited.

PURPOSE

Evaluate the clinical and radiographic outcomes of conversion total hip arthroplasty (THA) using a modular stem following a CMN failure.

MATERIALS AND METHODS

We retrospectively reviewed a consecutive series of patients with an IHF between 2012 and 2014 to identify CMN patients that went on to the subsequent failure and conversion to THA utilising a modular femoral stem (MFS). In all cases, MP Reconstruction Prosthesis (Waldemar Link, Hamburg, Germany) was implanted. Primary clinical outcomes were assessed using Harris Hip Score (HSS) before conversion procedure, 3 months, 6 months and recent office visit post-conversion THA thereafter. The secondary outcome was to analyse intra and postoperative complications. Serial radiographs at each follow-up interval were assessed for clinical success or to confirm adverse events.

RESULTS

28 patients were included in the study; 17 were females. The average age was 72.7 years (SD ± 10.5); the average time from the index procedure to conversion THA was 12.6 months (SD ± 3.5). At baseline, average HHS was 42.1 (SD ± 3.6), improved to 80.7 (SD ± 5.1) at 3 months, 86.0 (SD ± 3.9) at 6-months which levelled off to 86.1 (SD ± 4.0) at final follow-up. There were 4 (14%) post-conversion complications: 2 dislocations, 1 superficial wound infection, 1 patient with symptomatic abductor deficiency. All 4 cases were conservatively treated successfully, the implants were retained, and the patients progressed without further issue.

CONCLUSIONS

MFSs allow to successfully treat failed CMN and adverse variations in femoral anatomy with a device that will permit simultaneous correction of leg length, offset and version to relieve pain, restore function and create a durable prosthetic to host composite.

Observational study of a new modular femoral revision system

BACKGROUND

The uncemented Arcos^TM Modular Femoral Revision System (ARCOS) is a new comprehensive, press-fit revision design. The modular design offers a wide range of possible combinations to accommodate different variations of anatomy and bone stock. The ARCOS is made by a proximal body and a distal stem. As probably the only ones worldwide we predominantly use a combination of body and stem which supports proximal fixation and load, since this mimics the concept of the primary total hip arthroplasty with proximal weight-bearing, leading to bone stock preservation and no stress shielding or thigh pain.

AIM

To evaluate the early results after femoral revision in a consecutive series of patients undergoing surgery over 3 years.

METHODS

We included 116 patients in the study. They were operated in the period August 2011 to December 2014 and we got a clinical mean observation time of 4 (0.5-6) years. Clinical and radiographical follow-up included present function of the hip assessed by Harris Hip Score, Oxford Hip Score, and EQ5D (measure of health outcome). Of the 116 patients, 17 died in the interim and were consequently included only in the implant survivorship analysis; 46 patients attended the follow-up control.

RESULTS

In total 6 (5%) hips were re-revised due to infection (n = 3), fracture (n = 2) or subsidence (n = 1). No patient was re-revised due to aseptic loosening. The 1-, 2- and 5-year probability of implant survival (95%CI) were 97% (93%-100%), 97% (93%-100%) and 96% (92%-99%), respectively. In this cohort 95 patients received a combination of a proximal broach and a distal curved and slotted stem (BS), aiming for proximal fixation and load bearing; 21 patients received a different combination. When comparing these two groups the BS-group had a 5-year implant survival probability (95%CI) of 97% (93%-100%) compared with the group of other combinations with a 5-year implant survival probability (95%CI) of 90% (78%-100%) (P = 0.3). Our regression analysis showed that periprosthetic fracture as an indication for the ARCOS operation was the only significant negative outcome predictor. The mean Harris Hip Score result (100 points being best) was 83 (range 5-98). The mean Oxford Hip Score result (48 points being best) was 40 (range 19-48).

CONCLUSION

The early results of the ARCOS are promising compared with similar studies. We encourage the use of the BS combination whenever the bone stock proximally is adequate.

Distal non-traumatic fracture of the cementless MP stem: A case report and review of previous reported cases

Modular hip stems offer many advantages in revision arthroplasty. However, the region of modularity is prone to failure. Fracture of the non-cemented fluted tapered titanium Modular Prosthesis (MP) stem is relatively rare. We present here a case of a distal non-traumatic fracture of the MP stem and review the previously reported cases. A 53-years old, relatively active, male patient with a body mass index (BMI) of 37 kg/m² had a fracture of the non-cemented MP stem on the left side after five years without complaints. The BMI was 45 at the time of implantation of the MP stem. His weight was significantly reduced, but the stem failed and fractured at an atypical site, quite distal to the modular junction. The broken stem with a relatively small diameter had been exchanged to a larger one. Fracture of the non-cemented fluted proximally-modular distally-tapered titanium MP stem might occur after years. Even in cases of good bone quality of the proximal femur, patient BMI and activity level should be considered when selecting the stem diameter. Furthermore, proximal bone loss of the femur should be considered as a potential cause of failure.

Clinical and radiographic outcomes of total hip replacement with a 3-part metaphyseal osseointegrated titanium alloy stem enhanced with low plasticity burnishing: a mean 5-year follow-up study

Background

This study evaluates midterm results of a 3-part titanium alloy stem with metaphyseal fixation and a neck-metaphyseal taper junction strengthened with low plasticity burnishing (LPB). Our hypothesis is that this multimodular implant with LPB succeeds in offering the advantages of three-part modularity without junctional failure.

Methods

Twenty-eight of 32 complex primary (n = 9) and revision (n = 9) total hip arthroplasties were accounted for with minimum 2-year follow-up. Clinical and radiographic data were reviewed at a mean follow-up period of 60 months. One stem, removed for failure to osseointegrate, was submitted for sectioning and taper examination.

Results

There were no modular junction failures despite body mass indices of 20 to 40 and offsets of 34 to 47 mms. Implant survival was 96.3%, with one removal due to aseptic loosening in a patient with chronic renal failure. Taper analyses of the removed implant showed minimal damage. Preoperative and postoperative Harris Hip Scores and Oxford Hip Scores were 20 to 86 and 16 to 41, respectively. Patient satisfaction was 9.7/10. Radiographs showed stem subsidence >2 mm and radiolucencies around the metaphyseal cone only in the hip requiring implant removal.

Conclusions

This 3-part titanium alloy modular stem with LPB of the neck-metaphyseal taper junction showed good functional and radiographic results at a mean 5 years without junctional failures. Although this follow-up exceeds previously published reports, longer follow-up will be important to confirm our confidence in the additional strengthening provided by LPB.

Outcomes of neck modularity in total hip arthroplasty: an Italian perspective

BACKGROUND

The aim of this study is to conduct a systematic review of clinical outcomes and complications of modular neck THA among Italian cohorts.

METHODS

Only reviewed publications focused on Italian cohort patients in English language were considered for inclusion. Studies were included if they involved patients who underwent total hip replacement surgery with modular necks, and reported aetiology or survival rate or bone stability or clinical scores or complications.

RESULTS

The studies included in our search reported data on 3714 patients and 3856 hips. Most of the studies were from high-volume surgery centres. The most frequent diagnosis was osteoarthritis that occurred in 2910 cases (75.9%). The average survival rate and average bone stability were 97.20% and 99.37%, respectively. The average HHS improved from 42.1 prior to surgery to 89.52 after surgery. Studies included in our search reported 40 complications. The most frequently reported complication was dislocation (40%).

CONCLUSION

This review showed excellent survival rate and bone stability and good clinical outcomes in Italian cohort patients treated with modular neck THA, and these clinical results are comparable with international cohort rates. This review suggests that modular implants represent a very satisfying choice when practised by expert orthopaedic joint surgeons.