Decreased Glenoid Retroversion Is a Risk Factor for Failure of Primary Arthroscopic Bankart Repair in Individuals With Subcritical Bone Loss Versus No Bone Loss.

PURPOSE: To determine whether glenoid retroversion is an independent risk factor for failure after arthroscopic Bankart repair. METHODS: This was a retrospective review of patients with a minimum 2-year follow-up. In part 1 of the study, individuals with no glenoid bone loss on magnetic resonance imaging (MRI) and who failed arthroscopic Bankart repair (cases) were compared with individuals who did not fail Bankart repair (controls). In part 2 of the study, cases with subcritical (<20%) glenoid bone loss as measured on sagittal T1 MRI sequences who failed arthroscopic Bankart repair were compared with controls who did not. For each part of the study, glenoid version was measured using axial T2 MRI sequences. Positive angular measurements were designated to represent glenoid anteversion, whereas negative measurements were designated to represent glenoid retroversion. Independent t tests were conducted to determine the association between glenoid version and failure after arthroscopic Bankart repair. RESULTS: There were 20 cases and 40 controls in part 1 of the study. In part 2, there were 19 cases and 21 controls. There was no difference in baseline characteristics between cases and controls. Among individuals with no glenoid bone loss, there was no difference in glenoid version between cases and controls (cases: 6.0° ± 8.1° vs controls: 5.1° ± 7.8°, P = .22). Among individuals with subcritical bone loss, cases (3.8° ± 4.4°) were associated with significantly less mean retroversion compared with controls (7.1° ± 2.8°, P = .0085). Decreased retroversion (odds ratio 1.34; 95% confidence interval 1.05-1.72, P = 20) was a significant independent predictor of failure using univariable logistic regression. CONCLUSIONS: While glenoid retroversion is not associated with failure after arthroscopic Bankart repair in individuals with no glenoid bone loss, decreased retroversion is associated with failure in individuals with subcritical bone loss. LEVEL OF EVIDENCE: Level 3: Retrospective review.

The Retroverted Dens: A Review of its Anatomy, Terminology, and Clinical Significance.

BACKGROUND: Little attention has been given to the retroverted dens within the existing medical literature. However, this finding can have a clinical impact, especially in patients with Chiari malformation type I (CM1), as it can have consequences for further treatment. METHODS: Using standard search engines, we performed a literature review of anatomical, radiologic, and clinical studies as well as pathologic and surgical considerations related to the retroverted dens. Key words for our search included retroverted dens; retroflexed dens; odontoid retroflexion; posterior inclination; and tilted dens. RESULTS: A retroverted dens is most commonly found in the pediatric population in relation to CM1. Research has demonstrated that high degree of dens angulation can result in significant anterior brain stem compression with the need for both anterior and posterior decompression in patients with symptomatic CM1. CONCLUSIONS: A greater degree of dens angulation can lead to neurologic symptoms secondary to spinomedullary compression. Therefore, correct measurements are essential as such findings can influence presurgical planning.

Acetabular Retroversion Is a Risk Factor for Less Optimal Outcome After Femoroacetabular Impingement Surgery.

BACKGROUND: Patients with acetabular retroversion are at risk of labral tear and hip pain. It is unknown whether femoroacetabular osteoplasty (FAO) without reverse periacetabular osteotomy can be used in these patients. This study evaluated the outcome of mini-open FAO in patients with acetabular retroversion and compared that to patients without acetabular retroversion. METHODS: Fifty-one patients (29 male, 22 female) with acetabular retroversion who had undergone FAO between 2007 and 2015 were identified. The minimum 2-year clinical and radiological outcome was compared with 550 patients without dysplasia or retroversion who underwent FAO by the same surgeon. The preoperative and postoperative alpha angle, center-edge angle, Tonnis grade, joint space, and presence of labral tear and chondral lesion were determined. RESULTS: The mean age in the retroversion cohort was 27.4 ± 9.5 years compared to 34.5 ± 11.2 years in the control. The mean follow-up was 4.8 ± 1.5 years for retroversion and 4.1 ± 1.2 years for the control. The mean preoperative Short-Form 36 Health Survey and modified Harris hip score were not different between the cohorts. At the latest follow-up, the mean modified Harris hip score and Short-Form 36 Health Survey were significantly lower in the retroversion group (75.4 and 76.5) compared to the control (83.4 and 85.6). There was a higher percentage of failure among retroversion patients (13.7%) compared to the control (2.5%). CONCLUSION: Acetabular retroversion resulting in femoroacetabular impingent may be treated by FAO, but the outcome appears to be less optimal compared to patients with femoroacetabular impingent and no evidence of dysplasia and acetabular retroversion. Hip preservation surgeons should be aware of this anatomic variation and possible inferior treatment results after FAO in these patients.

Should Acetabular Retroversion Be Treated Arthroscopically? A Systematic Review of Open Versus Arthroscopic Techniques.

PURPOSE: To compare patient-reported outcomes, progression of radiographic arthritis, revision rates, and complications for hips with acetabular retroversion treated by open versus arthroscopic methods. METHODS: The PubMed and EMBASE databases were searched in August 2016 for literature on the open and arthroscopic techniques using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) method. All studies published in the English language that focused on the surgical treatment of femoroacetabular impingement caused by retroversion were included. All arthroscopic procedures, such as acetabuloplasty and labral repair, and open procedures, including anteverting periacetabular osteotomy and surgical dislocation with osteoplasty, were included. Articles that did not describe how retroversion was defined were excluded, as were studies with less than 6 months' follow-up and fewer than 5 patients. Two authors screened the results and selected articles for this review based on the inclusion and exclusion criteria. All results were scored using the Methodological Index for Non-randomized Studies (MINORS) criteria. RESULTS: There were 386 results returned and 15 articles that met the inclusion criteria of this study. Among the studies, 11 reviewed arthroscopic techniques and 4 reviewed open surgical procedures. Both techniques yield good results based on patient-reported outcomes with minimal progression of osteoarthritis and low complication rates. CONCLUSIONS: This review showed statistically and clinically significant improvements for the treatment of acetabular retroversion based on patient-reported outcomes, with low progression of radiographic arthritis, revision rates, and complications using both open and arthroscopic methods. LEVEL OF EVIDENCE: Level IV, systematic review of Level I to IV studies.

Unconstrained arthroplasty in type II valgus knees: posterior stabilized or cruciate retaining?

PURPOSE: Type II valgus knees are defined by medial collateral ligament laxity. This paper studies the results of posterior stabilized (PS) and cruciate retaining (CR) knee implants in type II valgus knees. METHODS: From 1999 to 2009, there were 100 type II valgus knees in 95 patients eligible for study (63 PS, 37 CR). Patients had prospectively collected clinical data up to 2 years after surgery. RESULTS: At 24 months after surgery, the CR group had reduced range of motion (PS: median 126.0°, CR: median 114°; n.s.) and a marginally but statistically significant increased valgus alignment (PS: median 5°, CR: median 6°; p = 0.011). Despite this, both groups produced equal and marked improvements in SF-36, function score and knee score of the Knee Society score, and Oxford knee score. CONCLUSIONS: Overall, both PS and CR implants performed equally well in type II valgus knees at 24 months post-operatively. Further longer-term studies would be warranted to assess for late instability. LEVEL OF EVIDENCE: Retrospective, Level III.

Joint line changes and outcomes in constrained versus unconstrained total knee arthroplasty for the type II valgus knee.

PURPOSE: The objective of this study was to compare the outcome of constrained and unconstrained primary total knee arthroplasty (TKA) in the management of the valgus deformity. METHODS: This is a retrospective review of patients with type II valgus knee who underwent primary TKA from 1999 to 2011. There were fifty patients in Group 1 who underwent varus-valgus constrained TKA. They were matched with another fifty patients in Group 2 who underwent unconstrained TKA. RESULTS: The mean joint line shift was significantly higher in Group 1 (+8 mm, SD 6 mm) than in Group 2 (+2 mm, SD 3 mm) (p = 0.03). At 2 years, there was no difference in anterior-posterior stability and mediolateral stability according to the Knee Society Score, and patients in Group 2 reported significantly better mean function score of 66.2 (SD 9.3) (mean 48, SD 7.1 in Group 1) (p = 0.002). Two patients (6 %) in Group 1 underwent revision surgery--one for a broken central peg and the other for aseptic loosening. Three patients (2 %) in Group 2 underwent revision surgery--two for global instability and one for poly wear. The estimated survivorship time was 8.3 years for constrained TKA and 12.0 for unconstrained TKA. CONCLUSION: Constrained TKA was associated with more significant joint line changes for the management of valgus arthritic knee, when compared with unconstrained TKA. LEVEL OF EVIDENCE: Retrospective study, Level III.

A new navigation-based technique for lateral distalizing condylar osteotomy in patients undergoing total knee arthroplasty with fixed valgus deformity.

PURPOSE: In a prospective, consecutive study, a navigation-based technique for calculating the sliding distance of the lateral epicondyle prior to osteotomy in TKA surgery of fixed valgus deformity has been developed, and early results have been evaluated. MATERIALS AND METHODS: Twenty-seven knees with a fixed valgus deformity undergoing TKA received this new treatment. Clinical scores and radiograph evaluation were performed preoperatively and 1-year postoperatively. Static and dynamic kinematic data were obtained from navigation at the beginning and at the end of surgery. RESULTS: The calculated amount of sliding distance varied between 5 and 16 mm. No complications regarding this technique occurred. All clinical scores showed a significant improvement, and radiological evaluation showed a correction of all parameters in 100 % of patients. CONCLUSION: With this navigation-based technique, it is possible to calculate the amount of sliding distance prior to osteotomy and obtain excellent early results. All axes have been corrected completely, and flexion and extension gaps were balanced. No specific complications of this technique have occurred so far. LEVEL OF EVIDENCE: II.

Coronal alignment is a predictor of the rotational geometry of the distal femur in the osteo-arthritic knee.

PURPOSE: There is a lot of inter-individual variation in the rotational anatomy of the distal femur. This study was set up to define the rotational anatomy of the distal femur in the osteo-arthritic knee and to investigate its relationship with the overall coronal alignment and gender. METHODS: CT-scans of 231 patients with end-stage knee osteo-arthritis prior to TKA surgery were obtained. This represents the biggest series published on rational geometry of the distal femur in literature so far. RESULTS: The posterior condylar line (PCL) was on average 1.6° (SD 1.9) internally rotated relative to the surgical transepicondylar axis (sTEA). The perpendicular to trochlear anteroposterior axis (⊥TRAx) was on average 4.8° (SD 3.3°) externally rotated relative to the sTEA. The relationship between the PCL and the sTEA was statistically different in the different coronal alignment groups (p < 0.001): 1.0° (SD 1.8°) in varus knees, 2.1° (SD 1.8°) in neutral knees and 2.6° (SD 1.8°) in valgus knees. The same was true for the ⊥TRAx in these 3 groups (p < 0.02).There was a clear linear relationship between the overall coronal alignment and the rotational geometry of the distal femur. For every 1° in coronal alignment increment from varus to valgus, there is a 0.1° increment in posterior condylar angle (PCL vs sTEA). CONCLUSION: The PCL was on average 1.6° internally rotated relative to the sTEA in the osteo-arthritic knee. The relationship between the PCL and the sTEA was statistically different in the different coronal alignment groups. LEVEL OF EVIDENCE: III.

Rotational limb alignment changes following total knee arthroplasty.

PURPOSE: The aim of the present study was to assess the changes in rotational alignment introduced by total knee arthroplasty (TKA) and the reproducibility of pre- and postoperative CT measurements of rotational limb alignment. METHODS: For this purpose we analyzed data from 196 consecutive cruciate-retaining, fixed bearing Columbus TKA procedures. Both pre- and postoperative scans torsion difference CT scans were available for measurements in 89 cases. Using these CT scans the neck-malleolar angle (NMA), the femoral posterior condylar angle (fPCA), the tibial posterior condylar axis (tPCA) and the tibial torsion angle (TTA) were independently assessed by three raters. CT scans were re-evaluated 8 weeks later by the most experienced rater for assessment of intraobserver agreement. RESULTS: Measurements of all angles were prone to high standard deviations reflecting interindividual variability. Mean fPCA changed from 1.3° to 2.7° internal rotation preoperatively to 0.1°-1.9° internal rotation postoperatively. Based on a relative external rotation of the tibial base plate as compared to the preoperative situation, we found a relative internal rotation of the postoperative NMA and tibial torsion of 3°-5.4° and 6°-7.5°, respectively. Intra- and interobserver agreement was strong for all angles assessed (ICCs 0.7-1.0) except for fPCA (ICC 0.2-0.6). However, mean absolute measurement differences for fPCA were clinically acceptable (1.2°-2.6°). CONCLUSIONS: Reproducibility of CT rotational limb alignment measurements was found to be clinically acceptable. Rotational alignment of the femoral and even more so of the tibial component will ultimately affect the rotational alignment of the entire limb-at least when fixed bearings are used. LEVEL OF EVIDENCE: Diagnostic study, Level III.

Simultaneous proximal femoral rotational and distal femoral varus osteotomies for femoral retroversion and genu valgum.

Whereas excess femoral anteversion and its related symptoms have been described many times, excess femoral retroversion is less well documented. We report the case of a 30-year-old woman who had a history of chronic bilateral hip and knee pain and evidence of excess femoral retroversion, genu valgum, early-onset lateral and patellofemoral compartment osteoarthritis of both knees, and hip arthritis. She experienced symptomatic relief after undergoing staged bilateral simultaneous proximal femoral rotational and distal femoral lateral opening wedge osteotomies. Although this combination of alignment problems is not an infrequent clinical occurrence, we have found no literature on this condition or treatment. The patient provided written informed consent for print and electronic publication of this case report.