Subspinal impingement: clinical outcomes of arthroscopic decompression with one year minimum follow up.

PURPOSE: This study was designed to (1) evaluate the clinical outcomes after arthroscopic subspinal decompression in patients with hip impingement symptoms and low AIIS, and to (2) assess the presence of low anterior inferior iliac spine on the pre-operative radiographs of patients with established subspinal impingement diagnosed intra-operatively. METHODS: Retrospective analysis of patients who underwent arthroscopic subspinal decompression has been performed. The indications for surgery were femoroacetabular impingement (FAI), or subspinal impingement. Pre-operative radiographs were assessed for anterior inferior iliac spine type. Intra-operative diagnosis of low anterior inferior iliac spine was based on the level of anterior inferior iliac spine extension relative to the acetabulum and the presence of reciprocal labral and chondral lesions. In patients where low anterior inferior iliac spine was not diagnosed on pre-operative radiographs, the pre-operative radiographs were re-read retrospectively to assess missed signs of low anterior inferior iliac spine. RESULTS: Thirty-four patients underwent arthroscopic subspinal decompression between 2012 and 2015. The patients were followed for a median of 25 months (13-37 months). Intra-operatively, grade 2 anterior inferior iliac spine was found in 27 patients and grade 3 anterior inferior iliac spine was found in 7 patients. MHHS, HOS, and HOSS scores increased from median (range) pre-operative scores of 55 (11-90), 48 (20-91) and 20 (0-80) to 95 (27-100), 94 (30-100) and 91 (5-100), respectively (p < 0.0001, p = 0.001, p < 0.0001, respectively). Pre-operative diagnosis of low AIIS was made in 6/34 patients via AP radiographs. On retrospective analysis of pre-operative radiographs, signs of low AIIS were still not observed in 21/34 (61.8%) patients. CONCLUSIONS: Arthroscopic subspinal decompression of low AIIS yielded significantly improved outcome measures and high patient satisfaction at a minimum of 13 months follow-up. Low AIIS is often under-diagnosed on AP pelvis and lateral frog radiographs and if left untreated, may result in unresolved symptoms and failed procedure. LEVEL OF EVIDENCE: IV.

Arthroscopic anterior inferior iliac spine decompression does not alter postoperative muscle strength.

PURPOSE: The purpose of this study was to assess the additional effect of anterior inferior iliac spine (AIIS) decompression on knee extensor and hip flexor strength and compare functional outcomes after arthroscopic FAI correction with and without AIIS decompression. METHODS: Sixty patients who underwent arthroscopic FAI correction surgery were divided into two groups matched for AIIS morphology: 31 patients who underwent arthroscopic FAI surgery only (without AIIS decompression) (FAI group) (AIIS Type I; n = 5, Type II; n = 26, Type III; n = 0) and 29 patients who underwent arthroscopic FAI surgery with AIIS decompression (AIIS group) (AIIS Type I; n = 5, Type II; n = 24, Type III; n = 0). Knee extensor and hip flexor strength were evaluated preoperatively and at 6 months after surgery. Patient-reported outcome (PRO) scores using the modified Harris hip score (MHHS), the nonarthritic hip score (NAHS) and iHOT-12 were obtained preoperatively and at 6 months after surgery. RESULTS: In the AIIS group, there was no significant difference between knee extensor strength pre- and postoperatively (n.s.). In the AIIS group, hip flexor strength was significantly improved postoperatively compared to preoperative measures (p < 0.05). In the FAI group, there were no significant improvements regarding muscle strength (n.s.). While there were no significant differences of preoperative and postoperative MHHS and NAHS between both groups (MHHS; n.s., NAHS; n.s.), the mean postoperative iHOT-12 in the FAI group was inferior to that in the AIIS group. (p < 0.01). The revision surgery rate for the AIIS group was significantly lower compared with that in the FAI group (p < 0.05). CONCLUSION: Anterior inferior iliac spine decompression, as a part of an arthroscopic FAI corrective procedure, had a lower revision surgery rate and did not compromise knee extensor and hip flexor strength, and it improved clinical outcomes comparable to FAI correction without AIIS decompression. AIIS decompression for FAI correction improved postoperative PRO scores without altering the muscle strength of hip flexor and knee extensor. LEVEL OF EVIDENCE: III.

No difference in prevalence of radiographic subspinal impingement of the hip between symptomatic and asymptomatic subjects.

PURPOSE: The study determined the prevalence of subspinal impingement (SSI) in symptomatic and asymptomatic individuals, morphologic characteristics in symptomatic patients, and risk factors for SSI. METHODS: The study cohort consisted of 427 patients (427 hips; median age 33.4 years; range 19-50 years) with mechanical symptoms who underwent multi-detector computed tomography arthrography (symptomatic patients) and 259 control (asymptomatic) patients who underwent abdominopelvic three-dimensional CT because of a ureter stone or minor trauma. Two orthopaedic surgeons reviewed the images to evaluate the prevalence of SSI and the relationship with morphologic abnormalities. Radiologic parameters were further compared between the SSI and non-SSI groups in symptomatic patients using the Chi-squared test or two-sample t test. Variables with p values <0.10 (sex and age) were included in the multi-variate analysis. Logistic regression analysis was carried out to identify independent risk factors for SSI. RESULTS: The prevalence of SSI in symptomatic and asymptomatic patients was 65/427 (15.2%) and 40/259 (15.4%), respectively (n.s.). Structural bony abnormalities in symptomatic patients were not associated with the presence of SSI (n.s.). Binary logistic regression analysis revealed that youth (odds ratio 0.952, 95% CI 0.922-0.984) was the only significant factor for SSI. CONCLUSIONS: SSI had a similar prevalence in symptomatic and asymptomatic patients and was not rare in either group. Therefore, clinical implication of SSI in symptomatic patient should be re-evaluated through further study. LEVEL OF EVIDENCE: Level IV.

Evaluation of soft tissue changes around the nose following subspinal Le Fort â osteotomy.

PURPOSE: This study sought to evaluate the effect of subspinal Le Fort Ⅰ osteotomy (SLFⅠO) and alar base chinch suture (ABCS) in preventing postoperative changes of nasal shape following maxillary movement of advancement-impaction (MAI) or advancement-downward (MAD) by analyzing changes of nasal soft tissue on computed tomography (CT) images. METHODS: Forty-three Japanese patients with dentofacial deformity who underwent orthognathic surgery with SLFⅠO and ABCS were retrospectively examined. Maxillary movement and changes to soft tissues around the nose were analyzed using pre- and postoperative CT. RESULTS: Increased nasal width and alar base width, upturning of the nasal tip and flattening of the nose occurred in both groups, with more prominent changes in MAI. MAD showed horizontal maxillary movement strongly correlated with changes in pronasale and subnasale. Preoperative nasal height correlated negatively with changes to nasal height in both groups, and to nasolabial angle and nasal tip angle in MAD. There were no correlations between the tightness of ABCS during operation and postoperative nasal soft tissue changes including nasal width. CONCLUSION: Postoperative changes to nasal shape following SLFⅠO and ABCS need to be considered with advance movements of the maxilla, regardless of vertical maxillary movement. Postoperative pronasale and subnasale may be estimable from the amount of the maxillary advance movement in MAD. Postoperative changes in nasal shape may be more prominent in cases with low nasal height.

Effectiveness of subspinal Le Fort I osteotomy in preventing postoperative nasal deformation.

PURPOSE: This study sought to determine the effectiveness of subspinal Le Fort I osteotomy (SLFIO) in preventing nasal deformation, by analyzing changes in the nasal profile on three-dimensional computed tomography (3D-CT) images. PATIENTS AND METHODS: The participants were 39 Japanese patients with mandibular prognathism (6 men and 33 women) who underwent bilateral sagittal split ramus osteotomy and Le Fort I osteotomy with maxillary advancement: SLFIO was performed in 20 patients and conventional Le Fort I osteotomy (CLFIO) in 19 patients. All patients underwent modified alar base cinch suture, V-Y closure, and reduction of the piriform aperture. CT data acquired before and 1 year after the surgery were evaluated three-dimensionally with software to determine changes in the nasal profile. RESULTS: Changes in alar width, alar base width, nasal length, and nasofrontal angle were significantly smaller following SLFIO than following CLFIO, although there were no significant differences in nasal projection, nasal tip angle, or nasolabial angle between two procedures. CONCLUSION: SLFIO for anterior repositioning of the maxilla can prevent undesirable transverse soft tissue changes of the nose.