The use of abduction bracing for the prevention of early postoperative dislocation after revision total hip arthroplasty

A Monocortical Screw for Preventing Trochanteric Escape in Extended Trochanteric Osteotomy: A Simple Solution to a Complicated Problem?

Extended trochanteric osteotomy (ETO) is an established method in revision total hip arthroplasty. Proximal migration of the greater trochanter fragment and the resulting non-union of the osteotomy remains a major problem, and several techniques have been developed to prevent its occurrence. This paper describes a novel modification of the original surgical technique in which a single monocortical screw is placed distally to one of the cerclages used for the fixation of the ETO. The contact between the screw and the cerclage counteracts the forces applied on the greater trochanter fragment and prevents trochanteric escape under the cerclage. The technique is simple and minimally invasive, does not require special skills or additional resources, or add to surgical trauma or operating time, and therefore represents a simple solution to a complicated problem.

A conservative approach to dislocation following total hip arthroplasty: a review of 8606 hips

PATIENTS AND METHODS

We present the data on 8606 total hip arthroplasty (THA) procedures carried out in 7818 patients through a posterior approach between 1998 and 2017.

RESULTS

218 hips (2.5%) suffered at least 1 dislocation with dislocation rates declining from 6.2% from 1998 to 2002 to 1.5% from 2003 to 2017. Overall, 92 hips (1.06%) required revision surgery but of these, only 5 (0.06%) had a full revision of both components with the remaining 87 requiring intervention only on the acetabular side. None have had a pseudo-arthrosis; none were left dislocated and all remain stable to date.

CONCLUSIONS

In patients who have a second dislocation within 3 months of their primary surgery we recommend a spica or long leg cylinder cast to reduce the need for revision surgery. We propose an algorithm to manage instability with less aggressive operative treatment in this often-elderly patient population with the potential for less physiological insult and significant cost savings.

Identification of risk factors for treatment failure of closed reduction and abduction bracing after first-time total hip arthroplasty dislocation

INTRODUCTION

After a first-time total hip arthroplasty (THA) dislocation, a closed reduction followed by partial immobilization in an abduction brace is the recommended therapy. Despite modern abduction braces the success rate of conservative therapy is limited and evidence is scarce. The aim of this study was to identify risk factors for failure of conservative treatment after THA dislocation.

MATERIAL AND METHODS

Eighty-seven patients, with conservative treatment of a first-time dislocation of a primary or revision THA, were included in this retrospective cohort study. Success was defined as a stable THA for a minimum of 6 months. Re-dislocation, open reduction or revision was defined as failure. The following risk factors were analyzed: gender, age, body mass index (BMI), ASA (American Society of Anesthesiologists) score, time of dislocation, head size, cup orientation, leg length, center of rotation and offset.

RESULTS

Sixty-seven percent of all patients experienced a re-dislocation, despite standardized conservative therapy. A BMI ≥ 25 kg/m², early THA dislocation, and low cup anteversion were associated with a statistically significantly higher risk for re-dislocation. None of the other risk-factors achieved statistical significance. A multifactorial risk-factor analysis was performed to assess whether a cup position outside of Lewinnek's safe zone in combination with gender, BMI and time to dislocation showed statistical significance for re-dislocation. Both BMI ≥ 25 kg/m² and early dislocation showed a statistically higher failure rate. Cup position and gender were not significant.

CONCLUSIONS

BMI ≥ 25 kg/m², early THA dislocation and low cup anteversion were identified as significant risk factors for failure of conservative treatment with an abduction brace for first-time THA dislocation.

Do hip-abduction braces work?-A biomechanical evaluation of a commercially available hip brace

INTRODUCTION

Dislocations of the hip joint are a common and clinically relevant complication following total hip arthroplasty (THA). Hip-abduction braces are currently used following operative or non-operative treatment of THA dislocations to prevent re-dislocations. However, the clinical and biomechanical effectiveness of such braces is still controversial.

MATERIAL AND METHODS

A total of 30 volunteers were measured during standing and during sitting up and down from a chair task wearing a hip brace set at 70°, 90° or no hip flexion limitation. Range of motion of the hip joint was measured in all directions by an inertial sensor system. Further it has been evaluated if the range of motion would be reduced by the additional use of an arthrodesis cushion.

RESULTS

The use of a hip brace set up with flexion limitation did reduce hip ROM in all directions significantly compared to unhinged brace (p < 0.001-0.035). Performing the "sit down and stand-up task" the brace set up at 70° flexion limitation did reduce maximum hip flexion significantly (p = 0.008). However, in most cases the measured hip flexion angles were greater than the settings of the hip brace should have allowed. The additional use of a cushion can further limit hip motion while sitting up and down from a chair.

CONCLUSION

This study has demonstrated that hip-abduction braces reduce hip range of motion. However, we also found that to achieve a flexion limitation of the hip to 90°, the hip brace should be set at a 70° hip flexion limitation.

Novel Cemented Technique for Trochanteric Fixation and Reconstruction of the Abductor Mechanism in Proximal and Total Femoral Arthroplasty: An Observational Study

Background

Little evidence exists regarding the clinical outcomes of cemented trochanteric fixation for abductor mechanism reconstruction in proximal or total femoral replacements. Clinical outcomes were assessed for a novel cemented technique for trochanteric fixation in femoral megaprostheses.

Methods

A descriptive series of 13 patients who underwent proximal or total femoral arthroplasty from 2016 to 2019 were reviewed. Radiographic trochanteric displacement >1 cm defined construct failure. A Kaplan-Meier survival analysis was performed to determine survival rates for these cemented constructs. Demographic information was obtained to better characterize the patient population in whom this technique was used.

Results

Eleven patients were included (age = 63.6 years; 45.4% females; body mass index = 31.7). Mean time to final radiographic follow-up was 73.8 weeks. Three of 11 (27.2%) patients had construct failure. Overall, survival at 1 year was 81.8%. At 2 years, survival of cemented constructs was 65.5%. More construct failures occurred in patients who sustained a postoperative dislocation than in those who did not (P = .05).

Conclusions

This novel cemented trochanteric fixation technique for reconstruction of the abductor mechanism in femoral megaprostheses had 81.8% survival at 1 year postoperatively. While longitudinal comparative studies with larger samples are needed, the cemented technique may provide a viable alternative to traditional cementless methods of trochanteric fixation. Increased construct failure rates after postoperative dislocation highlight the importance of robust abductor reconstruction in these implants.

Hip and Knee Bracing: Categorization, Treatment Algorithm, and Systematic Review

Hip and knee braces or orthoses are often used to provide support after surgery and to prevent or reduce the severity of injuries. The braces are used for stabilization, immobilization, mechanical correction, and rehabilitation. Hip braces consist of stabilization and unloader variations, whereas knee braces are composed of knee sleeves and patellofemoral, prophylactic, unloader, and functional braces. Indications vary widely and depend on the type of brace. Hip braces can treat osteoarthritis to instability after total hip arthroplasty. Knee brace indications range from mild arthralgias to instability and osteoarthritis. Although braces are routinely used clinically, high-level evidence is sparse for their use. With this review, the different types and uses of hip and knee braces have been defined, and their indications exemplified in hopes of spurring future research.

Outcomes of Mixed Femoral Fixation Technique Using Both Cement and Ingrowth in Revision Total Hip Arthroplasty: Minimum 2-Year Follow-up

The use of a modular femoral stem in revision total hip arthroplasty (THA) has been increasing recently. However, complications such as subsidence, dislocation and stem fracture are still noted, especially in hips with high grade femoral deficiency. We retrospectively studied a consecutive 41 hips (40 patients) that underwent revision THA with allograft reconstruction of the proximal femur in conjunction with hybrid fixation (proximally cemented and distally press-fit) of a modular femoral component. At a mean follow-up of 5.2 years (2 to 8 years), no hips sustained dislocation, subsidence or fracture of the stem in the follow-up period. We provided evidence that this technique may be a good alternative in the management of proximal femoral bone loss during revision THA.

Dislocation following total hip replacement

BACKGROUND

Hip replacement ranks among the more successful operations on the musculoskeletal system, but it can have serious complications. A common one is dislocation of the total hip endoprosthesis, an event that arises in about 2% of patients within 1 year of the operation. Physicians should be aware of how this problem can be prevented and, if necessary, treated, so that the degree of trauma due to hip dislocation after hip replacement surgery can be kept to a minimum.

METHODS

The authors searched Medline selectively for pertinent publications and analyzed the annual reports of international endoprosthesis registries.

RESULTS

The rate of dislocation of primary hip replacements ranges from 0.2% to 10% per year, while that of artificial hip joints that have already been surgically revised can be as high as 28%, depending on the patient population, the follow-up interval, and the type of prosthesis. Patient-specific risk factors for displacement of a hip endoprosthesis include advanced age, accompanying neurologic disease, and impaired compliance. Patients should scrupulously avoid hip movements such as bending far forward from a standing position, or internal rotation of the flexed hip. Operation-specific risk factors include suboptimal implant position, insufficient soft-tissue tension, and inadequate experience of the surgeon. Conservative treatment is justified the first time dislocation occurs without any identifiable cause. If a mechanical cause of instability is found, then operative revision should be performed as recommended in a standardized treatment algorithm, because, otherwise, dislocation is likely to recur.

CONCLUSION

The dislocation of a total hip endoprosthesis is an emotionally traumatizing event that should be prevented if possible. Preoperative risk assessment should be performed and the operation should be performed with optimal technique, including the best possible physical configuration of implant components, soft-tissue balance, and an adequately experienced orthopedic surgeon.

[Diagnostics and therapy of luxation after total hip arthroplasty]

BACKGROUND

Luxation following endoprosthetic hip replacement represents a frequent and severe complication and is the reason for a relevant number of hip arthroplasty revision interventions. The probability of occurrence of luxation of a total hip arthroplasty is associated with the indications, patient and operation-specific risk factors. Approximately 50 % of luxations after total hip arthroplasty occur within 3 months of the operation (early luxation).

DIAGNOSTICS

The diagnostics of luxation of total hip arthroplasty are carried out by clinical and radiological methods. The causative assignment is made by assessment of joint stability, the bony situation (e.g. loosening, periprosthetic fracture and defects) and the soft tissue (e.g. pelvitrochanterian musculature). In cases of clinical and paraclinical signs of infection and of late luxations, a joint puncture is indicated.

THERAPY

Therapy decisions are made depending on the cause (e.g. implant malpositioning, pelvitrochanterian insufficiency, impingement, incongruence between head and inlay and combinations of causes). Therapy of acute total hip prosthesis luxation begins with imaging controlled repositioning carried out with the patient under adequate analgesia and sedation. Conservative therapy is carried out by immobilization with a hip joint orthesis or pelvis-leg cast for 6 weeks. Operative therapy strategies for recurrent luxation are restoration of the correct implant position and sufficient soft tissue tension. Larger hip heads, bipolar heads and tripolar cups are more commonly used due to the geometrically lower probability of dislocation (higher jumping distance). Luxation of total hip prostheses due to infection is treated according to the principles of periprosthetic infection therapy. The rate of recurrence of luxation of 30 % is high so that in cases of unsuccessful therapy treatment should best be carried out in a center for revision arthroplasty.

CONCLUSIONS

The search for the exact cause of total hip prosthesis luxation is extremely important. A classification is only possible when the exact cause is known and together with patient and implant-specific details the therapeutic approach can be ascertained. In revision operations the intraoperative functional diagnostics must be exactly documented. The reasons for delayed luxations could be prosthesis infections, abrasion and loosening.

Are short fully coated stems adequate for "simple" femoral revisions?

BACKGROUND

Many studies suggest long femoral components should be used in revision THA. However, longer stems are more difficult to insert and reduce femoral bone stock for future revisions.

QUESTIONS/PURPOSES

We investigated (1) how frequently a short (≤ 160-mm or primary-length) fully porous-coated stem could be utilized for Paprosky Type I to IIIA femoral defects, (2) how often the tip of the old stem or cement mantle was bypassed by the revision implant, (3) Harris hip scores, radiographic signs of osseointegration, and revision frequency, and (4) complications associated with these reconstructions.

METHODS

Two surgeons performed 277 femoral revisions graded as Paprosky Types I to IIIA between 2004 and 2009. When femoral canal diameter was less than 18 mm, these surgeons generally used the shortest stem capable of achieving a minimum of 4 cm of scratch fit in the femoral isthmus. Patients were evaluated clinically using the Harris hip score and radiographically for component loosening and to determine whether the revision component bypassed the prior stem tip or cement mantle.

RESULTS

A short stem was utilized in 144 of the 277 revisions (52%). In 113 (78%), the revision femoral component did not bypass the tip of the prior stem or cement mantle. The Harris hip score improved (p < 0.001) from 36 preoperatively to 76 at a mean of 4 years (range, 2-8 years). Twelve stems required repeat revision including six (4.9%) for failed ingrowth. Complications included four intraoperative fractures, three postoperative femoral fractures, one cortical perforation, and eight dislocations.

CONCLUSIONS

Primary-length extensively coated stems provided reliable fixation for ½ of our Paprosky Type I to IIIA femoral revisions. When considering the use of such a component, the revision surgeon should take into account a small risk of failed osseointegration and technical challenges associated with this technique.

Risk factors for dislocation after revision total hip arthroplasty

BACKGROUND

Despite dislocation being the most frequent complication after revision THA, risk factors for its occurrence are not completely understood.

QUESTIONS/PURPOSES

We therefore (1) determined the overall risk of dislocation after revision THA in a large series of revision THAs using contemporary revision techniques, (2) identified patient-related risk factors predicting dislocation, and (3) identified surgical variables predicting dislocation.

METHODS

We performed 1211 revision THAs between June 2004 and October 2010 in 576 women and 415 men who had a mean age of 64.7 years (range, 25-95 years) at time of surgery. Forty-six (4%) were lost to followup and 13 died (1%), leaving 1152 hips followed for a minimum of 90 days (mean, 2 years; range, 90 days to 7.1 years). Multivariate logistic regression was performed to identify risk factors for dislocation. The model was also tested on patients followed for a minimum 1 year to assess any difference in longer followup.

RESULTS

One hundred thirteen patients dislocated over the followup period (9.8%). Factors that were different between patients who dislocated and those who remained stable included a history of at least one previous dislocation (odds ratio [OR] = 2.673), abductor deficiency (OR = 2.672), and Paprosky acetabulum class (OR = 1.522). Use of a constrained liner (OR = 0.503) and increased femoral head size (OR = 0.942) were protective against dislocation, while with longer followup a constrained liner was no longer significant.

CONCLUSIONS

Dislocation remains a common problem after revision THA. Identifying these risk factors can assist in patient education and surgical planning. Recognition of these risk factors in both patient type and surgical strategy is important for the surgeon performing revision THA and for minimizing these risks.

LEVEL OF EVIDENCE

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

Poor long-term clinical results of saddle prosthesis after resection of periacetabular tumors

BACKGROUND

The saddle prosthesis originally was developed to reconstruct large acetabular defects in revision hip arthroplasty and was used primarily for hip reconstruction after periacetabular tumor resections. The long-term survival of these reconstructions is unclear.

QUESTIONS/PURPOSE

We therefore examined the long-term function, complications, and survival in patients treated with saddle prostheses after periacetabular tumor resection.

PATIENTS AND METHODS

Between 1987 and 2003 we treated 17 patients with a saddle prosthesis after periacetabular tumor resection (12 chondrosarcomas, three osteosarcomas, one malignant fibrous histiocytoma, one metastasis). During followup, 11 patients died, resulting in a median overall survival of 49 months (95% CI, 30-68 months). The remaining six patients were alive without disease (mean followup, 12.1 years; range, 8.3-16.8 years). In one patient the saddle prosthesis was removed after 3 months owing to dislocation and infection. We obtained SF-36 questionnaires, Toronto Extremity Salvage Scores (TESS), and Musculoskeletal Tumor Society (MSTS) scores.

RESULTS

Thirteen of 17 patients used walking assists for mobilization at last followup: eight patients required two crutches, five needed one crutch, and one did not use any walking aids. The other three patients were not able to mobilize independently and only made bed to chair transfers. The mean hip flexion in the six surviving patients was 60° (range, 40°-100°) at last followup. Local complications were seen in 14 of the 17 patients: nine wound infections, seven dislocations, and two leg-length discrepancies requiring additional surgery. In the five surviving patients with their index prosthesis still in situ, the mean MSTS score at long-term followup was 47% (range, 20%-77%), the mean TESS score was 53% (range, 41%-67%), and the mean composite SF-36 physical and mental component summaries were 43.9 and 50.6, respectively.

CONCLUSION

Reconstruction with saddle prostheses after periacetabular tumor surgery has a high risk of complications and poor long-term function with limited hip flexion; therefore, we no longer use the saddle prosthesis for reconstruction after periacetabular tumor resections.