Instability in Patients with Lumbar Spine Disease or Fusion Undergoing Posterior Approach vs. Lateral Approach Primary Total Hip Arthroplasty

Background and Hypothesis: Dislocation rates after total hip arthroplasty (THA) in patients with fixed spinopelvic motion due to lumbar spine disease or fusion have been reported as high as 20%. Few studies exist that compare dislocation rates in patients with spine pathology undergoing THA via different surgical approaches. The purpose of this study was to compare postoperative dislocation rates in patients with lumbar spine disease or fusion between those undergoing a primary THA using a posterior versus direct lateral surgical approach. Experimental Design or Project Methods: With IRB approval, 1,205 primary THAs performed by two surgeons were retrospectively reviewed. One surgeon routinely performs THAs with a posterior approach while the other surgeon routinely uses a direct lateral approach. Chart review from the electronic medical record was conducted to identify patients who have lumbar spine disease or a lumbar spine fusion. Dislocations for patients with and without lumbar spine disease were compared by posterior approach and direct lateral approach. Results: 767 posterior approach and 431 direct lateral approach THAs were available for analysis. 43.6% of all THAs had lumbar spine pathology (337/767 posterior and 185/431 direct lateral). The overall dislocation rate was 1.26% (15/1195). The main predictors of dislocation in binary logistic regression were the presence of lumbar spine pathology (OR 5.24, 95% CI: 1.47–18.69, p=0.018) and posterior surgical approach (OR 7.93, 95% CI: 1.04–60.6, p=0.046). The dislocation rate for direct lateral approach THAs with lumbar spine pathology was significantly lower compared to posterior approach THAs with lumbar spine pathology (0.0% vs 3.6%, p=0.011). Conclusion and Potential Impact: Although there were few dislocations, the study results suggest a direct lateral approach for primary THA may be beneficial to reduce postoperative dislocation for patients with limited spinopelvic motion due to lumbar spine pathology.

Conjoined tendon preserving posterior approach in hemiarthroplasty for femoral neck fractures: A prospective multicenter clinical study of 322 patients

Purpose The posterior approach is widely used in femoral hemiarthroplasty. The major problem with this approach is the high risk of postoperative dislocation. A modified posterior approach, the conjoined tendon preserving posterior approach (CPP), was developed to reduce postoperative dislocations. The objective of this multicenter study was to evaluate the efficacy and safety of hemiarthroplasty performed using the CPP approach for femoral neck fractures. Methods A total of 322 patients with femoral neck fracture, from 10 facilities, were prospectively studied. Bipolar hemiarthroplasty using the CPP approach was performed, using the same type of implants. Hip joint movement was not restricted following surgery, regardless of a patient’s cognitive status. Final follow-up was performed 9.1 ± 1.5 months after surgery. Results Hemiarthroplasty was undertaken in 320 patients using the CPP approach. The mean age, operative time, and intraoperative blood loss were 83.3 ± 7.4 years, 70.0 ± 22.7 min, and 134.8 ± 107.9 mL, respectively. No postoperative dislocations were observed during the study period. Intraoperative adverse events related to the hip joint included femoral fractures in five patients (1.6%) and trochanteric fractures in four patients (1.3%). Postoperative hip joint adverse events included a periprosthetic fracture in one patient (0.3%), deep infection in two patients (0.6%), and stem subsidence in one patient (0.3%). Postoperative deaths occurred in 23 patients (7.2%). One patient (0.3%) had a severe non-hip adverse event unrelated to surgery that prevented independent living, while five patients (1.6%) had a moderate non-hip adverse event that required treatment. Conclusion The CPP approach prevented postoperative dislocation following femoral hemiarthroplasty in elderly patients, with no CPP-associated specific adverse events.

Clinical outcomes and predictive factors for failure with MPFL reconstruction combined with tibial tubercle osteotomy and lateral retinacular release for recurrent patellar instability

Background Medial patellofemoral ligament (MPFL) reconstruction combined with tibial tubercle osteotomy (TTO) and lateral retinacular release (LRR) is one of the main treatment methods for patellar instability. So far, few studies have evaluated the clinical effectiveness and assessed potential risk factors for recurrent patellar instability. Purpose To report the clinical outcomes of MPFL reconstruction combined with TTO and LRR at least three years after operation and to identify potential risk factors for recurrent patellar instability. Methods A retrospective analysis of medical records for patients treated with MPFL, TTO and LRR from 2013 to 2017 was performed. Preoperative assessment for imaging examination included trochlear dysplasia according to Dejour classification, patella alta with the Caton-Deschamps index (CDI), tibial tubercle–trochlear groove distance. Postoperative assessment for knee function included Kujala, IKDC and Tegner scores. Failure rate which was defined by a postoperative dislocation was also reported. Results A total of 108 knees in 98 patients were included in the study. The mean age at operation was 19.2 ± 6.1 years (range, 13–40 years), and the mean follow-up was 61.3 ± 15.4 months (range, 36–92 months). All patients included had trochlear dysplasia (A, 24%; B, 17%; C, 35%; D, 24%), and 67% had patellar alta. The mean postoperative scores of Tegner, Kujala and IKDC were 5.3 ± 1.3 (2–8), 90.5 ± 15.5 (24–100) and 72.7 ± 12.1 (26–86). Postoperative dislocation happened in 6 patients (5.6%). Female gender was a risk factor for lower IKDC (70.7 vs 78.1, P = 0.006), Tegner (5.1 vs 6.0, P = 0.006) and Kujala (88.2 vs 96.6, P = 0.008). Age (p = 0.011) and trochlear dysplasia (p = 0.016) were considered to be two failure factors for MPFL combined with TTO and LRR. Conclusion As a surgical method, MPFL combined with TTO and LRR would be a reliable choice with a low failure rate (5.6%). Female gender was a risk factor for worse postoperative outcomes. Preoperative failure risk factors in this study were age and trochlear dysplasia. Level of Evidence Level IV; Case series

What Factors Reduce the Incidence of Early Dislocations in Aseptic Total Hip Revisions with Stem Retention?

It is unclear which factors are the most important protectors for early postoperative dislocation in aseptic total hip arthroplasty (THA) revisions with stem retention. Therefore, we sought to determine what factors reduce the incidence of dislocations among these patients. Single institution retrospective review was made of 83 consecutive aseptic THA revisions of the head/liner and/or cup performed by five surgeons between 2017 and 2020. Periprosthetic infections and femoral component revisions were excluded. Demographics, preoperative diagnosis, revision type, surgical approach, use of dual mobility systems, length of stay, skin-to-skin time, transfusions, complications, and dislocations were assessed. Pearson correlation/logistic regression analyses were used to determine association/independent predictors of dislocation; α was set at 0.05. The overall dislocation rate was 12%. In Pearson correlation, only preoperative diagnosis (instability vs. other, −0.241, p = 0.028) and revision type (only liner vs. cup, −0.304, p = 0.005) were significantly associated with dislocations. In logistic regression, only preoperative diagnosis other than instability (odds ratio [OR] = 0.235, p = 0.038) and cup revision (OR = 0.130, p = 0.014) were found significant protectors against dislocation. Surgical approach and dual mobility systems were not independent predictors of dislocations (p = 0.184 and p = 0.083, respectively). Dislocation rates were significantly different between those cases that had the cup revised (4.0%) and those that did not (24.2%; p = 0.012). Preoperative diagnosis other than instability and cup revision seemed to be protective against early dislocation. Revision of the cup, in particular, seemed to be the most important factor to avoid dislocations while use of dual mobility liners per se did not significantly reduce that risk. The role of isolated liner exchanges in revision THA continues to evolve and should be reserved for appropriately selected patients.

Sulcus-Deepening Trochleoplasty for Trochlear Dysplasia

Background: Patients who are refractory to initial management of trochlear dysplasia, which consists of bracing and physical therapy, may be candidates for trochleoplasty. Indications: Indications for trochleoplasty include Dejour classification type B or D trochlear dysplasia, supratrochlear spur height ≥7 mm, and a positive J sign on examination. Technique Description: The thick shell sulcus-deepening trochleoplasty technique involves removing the supratrochlear spur by creating a 5-mm–thick osteochondral shell with underlying cavity, dividing the thick shell into medial and lateral leaflets, and securing the leaflets with absorbable sutures. This establishes a new trochlear groove that is flush with the anterior cortex of the femur. Results: A review of 21 studies with length of follow-up from 8.8 months to 15 years found postoperative dislocation was present in 0% to 15% of patients and the patient satisfaction ranged from 81.0% to 94.4%. A prospective study with a minimum 2-year follow-up found no cases of recurrent dislocation, no progression of radiographic arthritis, 84.8% of patients returned to sport, and the patient satisfaction was a 9.1/10. Discussion/Conclusion: Sulcus-deepening trochleoplasty for trochlear dysplasia provides patellar stability and excellent patient satisfaction.

Variations in Glenohumeral Bony Morphology May Predict Recurrent Instability after Arthroscopic Bankart Repair

Objectives: Variations in bony anatomy may be associated with failure of stabilization surgery. The aim of this study was to develop a method to measure bony morphology on magnetic resonance imaging (MRI) to identify risk factors for failure after Bankart repair. Methods: This was a retrospective case-control study of 118 patients. Cases of postoperative dislocation were compared to matched controls. Demographic data was obtained by chart review and radiographic data from preoperative MRI. Volume was measured using a 3-D model. Radius of curvature of the humeral head and glenoid was measured on axial MRI images. Statistical analysis used student’s t-test for continuous variables and either Fisher’s exact or Chi-squared test for categorical variables; P value < 0.05 was significant. Interrater reliability between reviewers was calculated using interclass correlation coefficients (r). Results: Forty-six patients who had a postoperative dislocation met inclusion criteria and were matched to 72 controls. There was no difference between groups for demographic (age, sex, percentage of contact athletes) or radiographic (glenoid bone loss, off-track Hill-Sachs lesions) parameters. The average number of preoperative dislocations was higher in the case group (3.2 vs. 2.0, p=0.003). The humeral head (68.8 ml vs 62.8 ml, p=0.05) volume was greater in the case group, though this did not reach statistical significance. Glenoid volume (13.5 ml vs 12.8 ml, p=0.31) was similar between groups. The radius of curvature of the glenoid was larger, or shallower, in the case group compared to the control group (23.6 mm vs 22.6 mm, p=0.05), though the difference did not reach statistical significance. A greater percentage of patients with a glenoid radius of curvature > 24.5 mm experienced a postoperative dislocation compared to those who had a smaller radius of curvature (62.0% vs 29.8%, p < 0.01). In fact, patients who had glenoid radius of curvature > 24.5 mm were 5 times as likely to experience a postoperative dislocation compared to those who did not (odds ratio 5.04, 95% CI 2.13 – 11.94, p < 0.01) There was no significant difference between the number of preoperative dislocations between patients with larger or smaller glenoid radius of curvature (2.6 vs 2.3, p = 0.55). There was a strong interrater reliability for measurement of humeral head volume, glenoid volume, radius of curvature of glenoid and radius of curvature of humeral head (r = 0.94, 0.88, 0.89, 0.95). Conclusion: The results of this study demonstrate that a larger radius of curvature, indicative of a shallower glenoid, is associated with failure following primary arthroscopic Bankart. These findings suggest that the bony concavity of the glenoid may play a role in stability. [Figure: see text]

Surgical implications of the hip-spine relationship in total hip arthroplasty

Total hip arthroplasty (THA) is considered the most successful orthopedic surgical procedure of the last century with excellent survivorship up to 20-years. However, instability remains a major issue representing the most common reason for revision after THA. Hip-spine relationship has gained progressive interest between arthroplasty surgeons and its understanding is crucial in order to identify high-risk patients for postoperative dislocation. Spinal deformity and abnormal spinopelvic mobility have been associated with increased risk for instability, dislocation and revision THA. Preoperative workup begins with standing anteroposterior pelvis x-ray and lateral spinopelvic radiographs in the standing and sitting position. Hip-spine stiffness needs to be addressed before THA in consideration of adapting the preoperative planning to the patient’s characteristics. Acetabular component should be implanted with different anteversion and inclination angles according to the pattern of hip-spine motion in order to reduce the risk of impingement and consequent dislocation. Different algorithmic approaches have been proposed in case of concomitant hip-spine disease and in case of altered sagittal balance and pelvic mobility. The aim of this review is to investigate and clarify the hip-spine relationships and evaluate the impact on modern total hip arthroplasty.

Bipolar hip arthroplasty in geriatric patients using a conjoined tendon-preserving posterior approach

Background In bipolar hemiarthroplasty (BHA), it is important to preserve soft tissue to reduce the risk of postoperative dislocation. While a variety of surgical approaches have been reported recently, extra care is needed with muscle- and tendon-preserving approaches in geriatric patients due to the fragility of their soft tissue. We investigated the usefulness of BHA using a conjoined tendon-preserving posterior (CPP) approach, which only dissects the external obturator muscle, in geriatric patients. Methods This retrospective study included 40 femoral neck fracture patients (10 men, 30 women) aged ≥ 80 years who underwent BHA using the CPP approach. The average age of the subjects was 85.8 years (80–94 years). We examined operation time, bleeding, preservation of short external rotator muscles, complications, and stem alignment and subsidence from postoperative radiographs. Results Although, gemellus inferior muscle injury was detected in 4 patients (10%), hip joint stability was very excellent in all cases. There was no intraoperative fracture and postoperative dislocation. On postoperative radiographs, all femoral stems were in a neutral position. There was no stem subsidence in all the patients. Conclusions BHA using the CPP approach was not associated with postoperative dislocation and appeared to be useful even in geriatric patients with soft tissue fragility.