Improved Functional Outcome Scores Associated with Greater Reduction in Cam Height Using the Femoroacetabular Impingement Resection Arc During Hip Arthroscopy

Minimal Clinically Important Difference, Substantial Clinical Benefit, and Patient Acceptable Symptom State Values After Hip Arthroscopy for Femoroacetabular Impingement Are Highly Dependent on Their Study Population and Calculation Methods: A Systematic Review

PURPOSE

To provide a summary of available literature on the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptom state (PASS) after hip arthroscopy for femoroacetabular impingement (FAI).

METHODS

A systematic review was conducted via the Cochrane Library, PubMed, Ovid MEDLINE, and Embase to identify studies that calculated MCID, SCB, or PASS for patient-reported outcome measures after hip arthroscopy for FAI. The electronic search strategy used was as follows: hip AND arthroscopy AND (MCID OR "minimal clinically important difference" OR SCB OR "substantial clinical benefit" OR PASS OR "patient acceptable symptom state"). Inclusion criteria were English-language studies published from 1980 to 2023 reporting clinical outcome scores and calculated values of MCID, PASS, or SCB for patients undergoing hip arthroscopy for FAI.

RESULTS

Forty-two studies (5 Level II, 19 Level III, and 18 Level IV) met inclusion and exclusion criteria. The most commonly used outcome measures across MCID, SCB, and PASS were the Hip Outcome Score sports-specific subscale and the activities of daily living subscale, the modified Harris Hip Score, and the 12-item international Hip Outcome Tool. The range of MCID values for Hip Outcome Score sports-specific subscale, Hip Outcome Score activities of daily living subscale, modified Harris Hip Score, and 12-item international Hip Outcome Tool were 7.2-15.7, 7.3-15.4, 7.2-16.8, and 8.8-16.2 respectively. Similarly, for SCB the values ranged from 77.9-96.9, 90.4-98.5, 20.0-98.4, and 66.7-87.5, respectively. Lastly, the PASS values ranged from 63.9-80.9, 85.9-99.2, 74.0-97.0, and 59.5-86.0, respectively.

CONCLUSIONS

MCID, SCB, and PASS values for patient-reported outcome measures after hip arthroscopy for the management of FAI are highly dependent on their associated study including study population and calculation methods.

LEVEL OF EVIDENCE

IV, systematic review of Level II-IV studies.

Postoperative alpha angle seems to be important for the achievement of clinical significance at a minimum 5-year follow-up after primary hip arthroscopy

The purpose of the present study was to clarify whether there is an association of postoperative alpha value with functional scores or progression of osteoarthritis at X-rays at the midterm after arthroscopic treatment of femoroacetabular impingement (FAI) syndrome with femoral osteoplasty, labral repair or debridement and rim trimming. A retrospective review of prospectively gathered data from 2013 to 2017 was performed. All patients who underwent first-time unilateral hip arthroscopy for FAI resection with 5-year follow-up were included. Patient-reported outcomes included the modified Harris Hip Score (mHHS) and Visual Analog Scale for Pain (Pain VAS). The progression of osteoarthritis (Tönnis grade) and radiological parameters (alpha angle, lateral center-edge angle [LCEA] and head-neck offset) were evaluated. A receiver operating characteristic (ROC) analysis was used to evaluate the correlation between significant variables and achievement of patient-acceptable symptomatic state (PASS) and degree of osteoarthritis. We identified 52 patients with a minimum 5-year follow-up (average, 6.7 years). The average patient age was 33.9 ± 11.5 years. There were 19 (36.5%) female patients. The mHHS improved from 60.1 ± 13.4 before surgery to 86.8 ± 14 after surgery (P < 0.001). The Pain VAS decreased from 6.21 before surgery to 2 after surgery (P < 0.001). Overall, 69% achieved the PASS for mHHS. The ROC curve for postoperative alpha angle demonstrated acceptable discrimination between patients achieving a fifth-year PASS value and those who did not have an area under the curve of 0.72. Patients having a postoperative alpha angle of ≤48.3° achieved the fifth-year PASS value at a significantly higher rate than patients having a postoperative alpha angle of >48.3° (P = 0.002). The postoperative alpha angle is a predictor of the achievement of the fifth-year PASS value for the mHHS. A threshold of ≤48.3° had a sensitivity of 0.75 and a specificity of 0.69 to predict positivity. Level of evidence IV.

Patients With Unhealed or Partially Healed Anterior Capsules After Hip Arthroscopy for Borderline Developmental Dysplasia of the Hips Have Inferior Patient-Reported Outcome Measures

PURPOSE

To evaluate the changes in anterior hip capsular thickness on pre- and postoperative magnetic resonance imaging (MRI) and their associated clinical outcomes in patients with borderline developmental dysplasia of the hip (BDDH).

METHODS

A minimum 2-year follow-up retrospective analysis was performed using data from symptomatic patients with BDDH who underwent hip arthroscopy with routine capsular closure between 2018 and 2020. An available postoperative hip MRI was a prerequisite for study inclusion. Capsular thickness at the capsulotomy zone was measured on MRI. An analysis of the correlations between anterior capsular thickness differences and demographic factors (including age, sex, body mass index, laterality, preoperative alpha angle and lateral center-edge angle, cartilage lesion grade, follow-up time, and capsule management) was performed. Patients with unhealed or partially healed capsules (study group) were propensity-score matched 1:1 to patients with completely healed capsules based on age, sex, body mass index, and follow-up time. Comparisons and analyses of the following parameters were completed for both groups: patient-reported outcomes (Hip Outcome Score-Activities of Daily Living [HOS-ADL], Hip Outcome Score-Sports-Specific Subscale [HOS-SSS], International Hip Outcome Tool 12-component form [iHOT-12], and modified Harris Hip Score), visual analog scale scores, radiographic measures, performed procedures, and complications.

RESULTS

Data were compiled for 59 patients' hips after patient selection. The majority of the repaired hip capsules remained closed (93.2%) at a minimum 2-year follow-up. Propensity-score matching was applied to distribute 25 subjects in the study group and 25 in the control group. The anterior capsule was significantly thinner postoperation in the study group (3.0 ± 1.2 mm vs 4.1 ± 0.6 mm; P < .001). Compared with the control group, patients in the study group had significantly inferior postoperative HOS-ADL (75.1 vs 83.5, P = .007), HOS-SSS (64.5 vs 77.1, P = .005), and iHOT-12 scores (56.1 vs 70.2, P = .006). In addition, patients in the study group were significantly less likely to achieve the minimum clinically important difference for the HOS-ADL score (52% vs 80%, P = .037) score and patient acceptable symptomatic state for the HOS-ADL score (32% vs 60%, P = .047).

CONCLUSIONS

The majority of the repaired hip capsules in patients with BDDH remained closed but not all capsules completely healed at a minimum 2-year follow-up. Patients with an unhealed or partially healed capsule had inferior HOS-ADL, HOS-SSS, and iHOT-12 scores and were less likely to achieve the minimum clinically important difference and patient acceptable symptomatic state for the HOS-ADL score.

LEVEL OF EVIDENCE

III, retrospective comparative prognostic study.

Extent of Cam Resection Relative to Epiphyseal Line and Its Association With Clinical Outcomes After Arthroscopic Treatment for Femoroacetabular Syndrome

Background:

Inadequate resection of cam lesions can cause inferior outcomes after hip arthroscopy and result in revision surgery for femoroacetabular impingement syndrome (FAIS).

Purpose:

To evaluate the association between postoperative cam lesions measured using the proximal boundaries of resection area (PBRE) relative to the epiphyseal line and 2-year outcomes after hip arthroscopy.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Included were patients with FAIS who had undergone primary hip arthroscopy between 2016 and 2018. The PBRE was calculated by measuring the linear distance from the PBRE to the epiphyseal line, dividing it by the diameter of the femoral head, and multiplying by 100; PBRE measurements were made at the 12-, 1-, and 2-o’clock positions on postoperative hip computed tomography. Within each clockface position, patients were divided into subgroups depending on whether their postoperative PBRE was greater than a half standard deviation above the mean (adequate resection) or less than or equal to a half standard deviation above the mean (inadequate resection). Patient-reported outcomes (PROs; Hip Outcome Score–Activities of Daily Living [HOS-ADL], International Hip Outcome Tool–Short Form [iHOT-12], modified Harris Hip Score [mHHS], and pain visual analog scale [VAS]) and rates of achieving the minimal clinically important difference (MCID) and patient-acceptable symptomatic state (PASS) were compared among the subgroups.

Results:

Included were 80 pairs of hips at 12 o’clock, 81 pairs of hips at 1 o’clock, and 80 pairs of hips at 2 o’clock. All subgroups demonstrated significant improvements in PRO scores at a minimum 2-year follow-up compared with preoperatively. At the 12-o’clock position, the subgroup with adequate resection had significantly superior HOS-ADL ( P = .004), iHOT-12 ( P < .001), and mHHS ( P < .001) scores and were more likely to achieve the MCID for the iHOT-12 score ( P = .035) and the PASS for the HOS-ADL ( P = .003), iHOT-12 ( P = .007), and mHHS ( P < .001) scores compared with the matched subgroup. There were no significant differences in PRO scores or rates of MCID and PASS for the 1- or 2-o’clock groups.

Conclusion:

The epiphyseal line may be a useful and reproducible landmark measurement for cam-type deformity. Patients considered to have inadequate resection at 12 o’clock had lower outcome scores at a minimum 2-year follow-up.