Is there a distinct pattern to the acetabular labrum and articular cartilage damage in the non-dysplastic hip with instability?
OBJECTIVE
The purpose of this study was to determine whether or not there is a distinct pattern of injury to the acetabular labrum and/or cartilage in the hip with instability without bony dysplasia.


METHODS
Surgical records and intra-operative images of consecutive patients who underwent primary hip arthroscopy for femoroacetabular impingement (FAI) and/or hip instability by the senior author from April 2007 to December 2014 were retrospectively reviewed. Pathological changes were documented and charted on a novel diagram of the acetabulum, and classified into eight patterns corresponding to the lesion's location and size. In patients who had acetabular chondroplasty treatment, the width of the cartilage lesion was recorded.


RESULTS
A total of 953 hips in 886 patients were included, and patients who met our inclusion/exclusion criterion were grouped into an Instability-Only group (45 hips), an Instability-Dysplasia group (12 hips), as well as Pincer-FAI, Cam-FAI, and Combined-FAI groups consisting of 100, 54, and 269 hips, respectively. In the Instability-Only group, 42.2 % of the chondral and labral lesions demonstrated a "Straight-Anterior" pattern, which proportion was statistically significantly different compared with Pincer-FAI (p < 0.000), Cam-FAI (p = 0.0002), and Combined-FAI (p < 0.000) groups. In Instability-Only patients, only 15.6 % of the lesions had an "Anterior to Lateral" pattern, a significantly lower proportion (p < 0.000) compared with the FAI groups. Also 11.1 % of the lesions demonstrated a "Lateral" pattern, which is a significantly greater proportion compared with Pincer-FAI (p < 0.000) and Combined-FAI (p < 0.000) groups. The mean width of the cartilage lesions for the Instability-Only group was 2.9 mm, which was significantly shallower than for the other FAI groups (p < 0.000).


CONCLUSIONS
A significant predilection of "Straight-Anterior" or "Lateral" location of labral and/or cartilage damage was observed in the hip with instability, while there was shallow width of articular cartilage damage in these patients. These results suggest that there is a distinctive labral and cartilage damage pattern for hips with instability without inherent bony dysplasia.


METHODS
Diagnostic study, Level IV.
Department of Orthopaedic Surgery, Nishi-Kobe Medical Center, 5-3-7 Kojidai Nishiku, Kobe, 651-2273, Japan. k6shibata@gmail.com.|Department of Orthopaedic Surgery, Stanford School of Medicine, Stanford, CA, 94063, USA. k6shibata@gmail.com.|Department of Orthopaedic Surgery, Kyoto University, Graduate School of Medicine, Kyoto, 606-8507, Japan. k6shibata@gmail.com.
Kotaro R
KR
Shibata
Department of Orthopaedic Surgery, Kyoto University, Graduate School of Medicine, Kyoto, 606-8507, Japan.
Shuichi
S
Matsuda
Department of Orthopaedic Surgery, Stanford School of Medicine, Stanford, CA, 94063, USA.
Marc R
MR
Safran
D000077:Acetabulum / Q000000981:diagnostic imaging* / Q000473:pathology; D000293:Adolescent; D000328:Adult; D002358:Cartilage, Articular / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D057925:Femoracetabular Impingement / Q000000981:diagnostic imaging* / Q000473:pathology; D051445:Fibrocartilage / Q000000981:diagnostic imaging* / Q000473:pathology; D006621:Hip Joint / Q000000981:diagnostic imaging*; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D012189:Retrospective Studies; D055815:Young Adult
Femoroacetabular impingement; Hip arthroscopy; Hip instability
J Bone Joint Surg Br. 1998 Jul;80(4):711-9
9699842
J Bone Joint Surg Br. 1986 May;68(3):400-3
3733805
Am J Sports Med. 2011 Jul;39 Suppl:92S-102S
21709038
J Bone Joint Surg Am. 2009 May;91(5):1120-9
19411460
Arthroscopy. 2011 May;27(5):628-36
21663720
J Bone Joint Surg Am. 1995 Jul;77(7):985-9
7608241
Clin Orthop Relat Res. 2007 Dec;465:16-22
17906586
J Bone Joint Surg Br. 1991 May;73(3):423-9
1670443
J Bone Joint Surg Am. 2008 Jul;90(7):1464-72
18594094
Clin Orthop Relat Res. 2003 Dec;(417):27-40
14646700
Clin Orthop Relat Res. 1996 Jun;(327):196-206
8641064
Clin Sports Med. 2011 Apr;30(2):293-315
21419957
Knee Surg Sports Traumatol Arthrosc. 2016 Jun;24(6):2016-23
25331654
Am J Sports Med. 2007 Nov;35(11):1918-21
17703000
Am J Sports Med. 2014 Nov;42(11):2627-33
25139303
Arthroscopy. 2005 Dec;21(12):1496-504
16376242
J Bone Joint Surg Br. 2005 Jul;87(7):1012-8
15972923
Am J Sports Med. 2016 Jan;44(1):39-45
26419897
Clin Orthop Relat Res. 2002 Dec;(405):122-8
12461363
Am J Anat. 1991 Sep;192(1):1-13
1750378
J La State Med Soc. 2013 Mar-Apr;165(2):88-93
23734538
Clin Sports Med. 2006 Apr;25(2):309-26, ix-x
16638494
J Bone Joint Surg Am. 2009 Jan;91(1):192-7
19122095
Sports Med Arthrosc. 2010 Jun;18(2):108-12
20473129
HSS J. 2011 Jul;7(2):145-50
22754415
Arthroscopy. 2007 Dec;23 (12 ):1295-302
18063173
Clin Orthop Relat Res. 2004 Jan;(418):67-73
15043095
J Bone Joint Surg Br. 2001 Mar;83(2):171-6
11284559
J Hip Preserv Surg. 2015 Jul;2(2):123-35
27011829
Ann Rheum Dis. 1998 Nov;57(11):676-81
9924210
J Bone Joint Surg Am. 1950 Jul;32-A(3):519-31
15428474
Clin Orthop Relat Res. 1998 Oct;(355):261-71
9917612
J Bone Joint Surg Am. 1953 Jan;35-A(1):65-80
13022708
J Bone Joint Surg Br. 2005 Sep;87(9):1192-6
16129740
Arthroscopy. 2003 Dec;19(10):1055-60
14673446
Arthroscopy. 2009 Apr;25(4):400-4
19341927
Clin Orthop Relat Res. 2004 Dec;(429):163-9
15577482
Clin Orthop Relat Res. 2003 Aug;(413):201-7
12897611
Clin Orthop Relat Res. 2015 May;473(5):1712-23
25524428
J Am Acad Orthop Surg. 2011 Jun;19(6):340-9
21628645
Clin Orthop Relat Res. 2003 Dec;(417):112-20
14646708
Knee Surg Sports Traumatol Arthrosc. 2017 Jan;25(1):3-8
27492383
Am J Sports Med. 2004 Oct-Nov;32(7):1668-74
15494331
Am J Sports Med. 2013 Nov;41(11):2591-8
23956133
Bone Joint J. 2013 Oct;95-B(10 ):1320-5
24078526
Am J Sports Med. 2010 Jun;38(6):1250-4
20392972