Female gender, decreased lateral center edge angle and a positive hyperextension–external rotation test are associated with ease of hip distractability at time of hip arthroscopy

Abstract

PurposeTo identify factors associated with ease of hip distraction at the time of hip arthroscopy. MethodsA retrospective review of patients 17–50 years old undergoing hip arthroscopy with a single high‐volume hip arthroscopist was performed from 2014 to 2020. Demographics, clinical history, examination, and imaging findings were collected. Distractibility was quantified using turns of fine traction (1 turn = 4 mm axial distraction) with the patient paralyzed on a fracture table with a well‐padded perineal post Fine axial traction was applied after the patient’s perineum contacted the post. Demographic and clinical predictors of ease of distractibility were analyzed with simple linear regression models. Significant predictors were subsequently added to a multivariable linear regression model, estimating the effect of each variable. ResultsIn total, 453 patients were included, with an average age of 31.6 years (± 9.2) and 45.9% females. In univariate analysis, gender, race, BMI, range of motion, hyperextension–external rotation (HEER) test, the abduction–extension–external rotation test, and lateral center edge angle (LCEA) were associated with the number of fine traction turns required to distract the hip. On multivariable analysis, lower LCEA (p = 0.002), female gender (p < 0.001), and a positive HEER test (p = 0.045) were associated with decreased turns required for adequate hip distraction. ConclusionFemale gender, decreased LCEA, and a positive HEER test are associated with decreased axial traction required for adequate hip distraction at the time of hip arthroscopy. As ease of distractibility has been associated with hip microinstability, these findings may allow pre‐operative identification of hip instability patients and aid in pre‐operative counseling, risk stratification and capsular management planning. Level of evidenceIV. Clinical relevancePreoperative identification of risk factors for ease of hip distraction may raise pre‐surgical suspicion and, when coupled with other intraoperative findings, may aid in the diagnosis and management of hip microinstability.

The traction force of the pulled limb in hip arthroscopic surgery is determined by stiffness coefficient which is significantly related to muscle volume

“…In other words, although the SC integrates the inluence of traction force and TW to a certain extent, a simple linear function is not suiciently accurate. In addition, some of the conclusions of a research which has a larger sample size are diferent from ours [5]. For example, it shows that BMI and LCEA are both related to the traction force when pulling the hip joint.…”

Hip microinstability diagnosis and management: a systematic review

“…Another study looked at sex difference in non-arthritic hip pathology, their findings showed that presence of generalized ligamentous laxity was significantly higher in female than male patients (38.6% vs 13.6% respectively) [28]. Female gender has also been associated with ease of hip distractibility at the time of hip arthroscopy [4]. This association between female gender and ligamentous laxity, may explain the higher prevalence of micro-instability seen among female patients.…”

Can Hip Passive Range of Motion Predict Hip Microinstability? A Comparative Study

“…We identified 69 patients with isolated hip microinstability (without bony FAI morphology) based on previously published intraoperative criteria (ease of hip distraction, residual hip subluxation after release of traction, straight anterior or lateral chondral and labral pathology). 4 , 6 , 7 , 14 , 15 , 22 , 26 …”

“…We identified 69 patients with isolated hip microinstability (without bony FAI morphology) based on previously published intraoperative criteria (ease of hip distraction, residual hip subluxation after release of traction, straight anterior or lateral chondral and labral pathology). 4,6,7,14,15,22,26 The force required for hip distraction was measured based on a consistent and standardized method, recorded as the number of turns of traction (1 turn ¼ 4 mm of axial traction) to obtain 10 mm of hip distraction, as has been previously reported. 6 The initial state was obtained by placing the patient firmly against a perineal post with body weight traction applied by the senior surgeon as previously described.…”

“…4,6,7,14,15,22,26 The force required for hip distraction was measured based on a consistent and standardized method, recorded as the number of turns of traction (1 turn ¼ 4 mm of axial traction) to obtain 10 mm of hip distraction, as has been previously reported. 6 The initial state was obtained by placing the patient firmly against a perineal post with body weight traction applied by the senior surgeon as previously described. 5,6 A diagnosis of hip microinstability was made based on 11 turns ( 44 mm of traction).…”