A Contemporary Look at the Evaluation and Treatment of Adult Borderline and Frank Hip Dysplasia

Abstract

Background: Adult hip dysplasia is often diagnosed according to the lateral center-edge angle (LCEA). Patients with frank hip dysplasia (LCEA <20°) traditionally require treatment with bony realignment through a periacetabular osteotomy (PAO) and/or derotational femoral osteotomy, while patients with borderline hip dysplasia (BHD) present a challenging treatment dilemma, as it remains unknown when they should be treated with hip arthroscopy and/or a PAO. Purpose: To perform a narrative review to report the differences in hip morphology and clinical outcomes between adult patients with frank hip dysplasia and BHD. Study Design: Narrative review. Methods: A systematic search of the literature was conducted through the Medline, EMBASE, and Cochrane databases with the search phrase borderline hip dysplasia. Results: The search identified 305 articles, of which 48 were considered relevant to this study after screening of titles and abstracts. Four articles discussed new radiographic means of evaluating adult hip dysplasia, 16 articles analyzed morphology of dysplastic hips, and 28 articles described the clinical outcomes of patients with frank hip dysplasia or BHD treated with hip arthroscopy and/or PAO. Because the level of evidence obtained from this search was not adequate for systematic review or meta-analysis, a current concepts review on the diagnosis, hip morphology, and clinical outcomes of patients with frank hip dysplasia or BHD is presented. Conclusion: Adult hip dysplasia is most commonly diagnosed based on the LCEA; however, the LCEA is an unreliable sole marker for dysplasia, and additional radiographic parameters should be utilized. Furthermore, specific pathology identified on imaging and/or during hip arthroscopy can provide clues to a surgeon when the diagnosis is inconclusive according to history and physical examination alone. While the data support that patients with frank dysplasia are best treated with PAO, there is no such preferred treatment for patients with BHD, who have a wide spectrum of instability. Selective use of arthroscopic labral and capsular treatment alone may provide good results in carefully chosen patients with BHD, while some may end up requiring a bony realignment procedure.

Revision Hip Arthroscopy in the Borderline Dysplastic Population: Reporting Outcomes With Minimum 2-Year Follow-up, With a Subanalysis Against a Propensity-Matched Nondysplastic Control Group

“…PAO has demonstrated to effectively alter the natural history of developmental dysplasia of the hip (DDH) 56 ; however, the role of PAO in borderline dysplasia is still an open question, with limited data available. 22,39 With 39 patients with borderline dysplasia, McClincy et al 38 reported good results after PAO, with a 94% survivorship rate at minimum 2-year follow-up.…”

“…In a recent systematic review, Kraeutler et al 22 noted that hip arthroscopy alone as an initial surgical treatment remains a viable option in patients with borderline dysplasia. Nonetheless, the authors emphasized that these studies represented short-term outcomes.…”

“…11,16,26,31 Alternatively, periacetabular osteotomy (PAO) has shown promise for short-term outcomes as well. 22,38 When arthroscopic management is used for this population, variables such as acetabular inclination, Tönnis grade for osteoarthritis, generalized ligamentous laxity, excessive femoral anteversion, and ligamentum teres tears have been established as potential risk factors for failure or conversion to total hip arthroplasty (THA). 17,22,34 Although a reasonable amount of data is currently available for patient-reported outcomes (PROs) for borderline dysplasia after primary arthroscopic surgery, 10 there has been a paucity of literature for this population in regard to PROs after revision hip arthroscopy.…”

How Can Patient-Reported Outcomes of Periacetabular Osteotomy be Improved? A Short-Term Follow-up of 79 Hips.

“…LCEA, acetabular coverage ratio, sharp angle and Tönnis angle were measured by Digimizer software (version 5.4.6) before and after the PAO. DDH is generally believed to exist with an LCEA<20° (24,25), acetabular coverage ratio < 75%(26), sharp angle>40° (27)and Tönnis angle>10°(28). In addition, according to previous studies (24,25), the preoperative LCEA was graded as follows: LCEA<5°, 5°< LCEA<20°, and LCEA>20°.…”

“…DDH is generally believed to exist with an LCEA<20° (24,25), acetabular coverage ratio < 75%(26), sharp angle>40° (27)and Tönnis angle>10°(28). In addition, according to previous studies (24,25), the preoperative LCEA was graded as follows: LCEA<5°, 5°< LCEA<20°, and LCEA>20°. According to Wells et al (21), a postoperative LCEA was graded as 20° < LCEA<38° and LCEA >38°.…”