Patients with hip dysplasia
Patients with developmental dysplasia of the hip (DDH) are particularly challenging for surgeons performing total hip arthroscopy (THA). Not only is this group more prone to complications, but surgically addressing structural abnormalities can result in significant lengthening of the femur during THA. Restoring equal leg length to obtain functionality is possible and several surgical techniques have been successful.
Developmental dysplasia of the hip (DDH) is a misalignment or deformation (congenital or developmental) of the hip joint . Women are eight times more likely than men to have the condition and it is the most common source of hip osteoarthritis in women younger than 40 years old . Clinical severity ranges from barely detectable to frank dislocation, and can occur bi- or unilaterally . Incidence rates have been estimated to be around 5 per 1,000 hips . It is also a risk factor for the development of hip osteoarthritis .
Classification of dysplastic hips
There are two accepted reliable classification systems  for dysplastic hips: Crowe  and Hartofilakidis . Eftekhar and Kerboul classifications were found to not be as reliable by Brunner et al .
Figure 1. Crowe classification for developmental dysplasia of the hip .
Korkmaz O, Malkoç M. In: Spasovski D, ed. Total Hip Replacement in Developmental Dysplasia of the Hip: Pitfalls and Challenges, Developmental Diseases of the Hip - Diagnosis and Management. 2017. InTech, DOI: 10.5772/67479. Available from: https://www.intechopen.com/books/developmental-diseases-of-the-hip-diagnosis-and-management/total-hip-replacement-in-developmental-dysplasia-of-the-hip-pitfalls-and-challenges.
Table 1. Crowe classification. Compiled from: Crowe JF, Mani VJ, Ranawat CS. Total hip replacement in congenital dislocation and dysplasia of the hip  and Wikipedia. Hip dysplasia .
Figure 2. Hartofilakidis classification for developmental dysplasia of the hip .
Benjamin B. Management of limb length problems during total hip replacement for patients with developmental dysplasia of hip.
Table 2. Hartofilakidis classification .
Krueger C. Adult Dysplasia of the Hip. OrthoBullets. Available at: http://www.orthobullets.com/recon/5008/adult-dysplasia-of-the-hip.
Complexity necessitates planning
Developmental dysplasia of the hip alters hip structure and mechanics, which make total hip arthroplasty (THA) a more complex procedure prone to complications and revision risks . Biju Benjamin, orthopedic surgeon at University College London Hospital says that in this patient “the hip will never be truly normal, and they have a higher risk of complications than any other patient that we treat.”
The higher rate of THA complications in the DDH population is attributed to a number of factors, such as the young age of patients, high activity level, and increased complexity of surgery . Some of the more common THA complications for DDH cases are: sciatic nerve palsies, hip dislocation, infection, limb length problems, mortality, and periprosthetic femur fracture [11, 12]. However, there are steps a surgeon can take both pre-and intraoperatively to help anticipate and address potential problems with leg length .
As discussed in Part 1 of this article series, preoperative investigations are critical information gathering opportunities. Go to Part 1 for more specific discussion about appropriate clinical examination tests and questioning.
For the DDH patient, it is just as important, if not more so, to piece together a full picture of what to anticipate during the procedure. Several conditions that could be encountered in the DDH patient [10, 11, 16-19] include:
- Callosities under the metatarsal heads from walking on tiptoes
- Postural deformities
- Gait irregularities
- Preexisting LLD
- Shallow, narrow, lateralized acetabulum; in cases of dislocation, true acetabulum is hypoplastic and invaded with adipose tissue
- Increased anteversion and deficiency of the anterior and superior walls of the acetabulum
- Misshaped and/or small proximal femur
- Increased femoral neck anteversion; narrow femoral canal
- Shortened and/or hypertrophic muscles
- A shorter sciatic nerve that can be injured in a posterolateral approach due its position
- Distorted femoral nerve and the profunda femoris artery increases risk of injury during surgery
Each case should be carefully analyzed and reconstruction options selected for their suitability . Of particular note in planning is assessing the bone sock of the acetabulum. If there is not enough to implant the acetabuluar cup then bone grafting and reconstruction systems may be needed . A patient's femur might display stenosis, bowing, shortening, and anteversion of the femoral neck .
Preoperative x-rays and templating
X-rays of the bilateral anteroposterior and lateral hip joint will help to evaluate bone quality, morphology, femoral dislocation distance, and the degree of shortening. CT scans have also been suggested as a useful and routine preoperative planning tool to assess structural abnormalities [11, 12, 19].
Biju Benjamin  recommends templating with more than one prosthesis design and to also perform lateral templating as proximal deformity of the femur may complicate stem insertion. Correlate all measurements with clinical observation since a short pelvic view can produce faulty x-ray measurement values . Meermans et al found that the interteardrop line and femoral head center are the best landmarks when assessing for LLD, particularly when the lessor trochanter is deformed or unclear [11, 20].
A tool box of techniques
As exhibited in the Crowe and Hartofilakidis DDH rating systems, dysplasia comes in varying degrees, and so do the surgical complexities; Crowe IV and Hartofilakidis Type 3 typify the most complex cases.
Orthopedic surgeon Jurek Pietrzak, based at University College London Hospital emphasized that “while achieving leg-length equality is a worthwhile goal, DDH patients must be aware that circumventing hip dislocation, avoiding neurological injury, and achieving primary component stability is foremost. In these patients over-lengthening is generally not a problem, but getting sufficient length is more difficult.”
The femur may require shortening during THA in the DDH patient and a number of techniques to do this have been described in the literature: greater trochanteric osteotomies , lesser trochanteric osteotomies , subtrochanteric osteotomies , femoral diaphysis shortening [24, 25], and distal femoral shortening . Fig 3 shows a case where a subtrochanteric shortening osteotomy was performed in two-stage THA on a patient with Crow Type IV DDH .
Figure 3. Preoperative plain x-ray showing Crowe type IV developmental dysplasia of the hip  (a). During the first stage, surgical hip liberalization with abductor slide and skeletal traction for 2 weeks were performed (b, c). During the second stage, a total hip arthroplasty and subtrochanteric shortening osteotomy were performed due to difficult reduction (d).
With permission: Yoon PW, Kim JI, Kim DO, et al. Cementless Total Hip Arthroplasty for Patients with Crowe Type III or IV Developmental Dysplasia of the Hip: Two-Stage Total Hip Arthroplasty Following Skeletal Traction after Soft Tissue Release for Irreducible Hips. Clin Orthop Surg. 2013 Sep; 5(3): 167–173. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3758985/.
DDH patients more frequently experience complications after THA and this has been attributed to their “abnormal anatomy, the larger soft-tissue release, possible osteotomies, and any lengthening of the limb” . Shortening the limb to restore leg length can result in nonunion at the osteotomy site due to inadequate fixation, or cement extrusion, in the case of cemented stems .
Additionally, the DDH cohort is at increased risk of pelvic obliquity and may evolve fixed spinal misalignment. The practitioner is encouraged to look for knee contractures and foot deformities as they may contribute to functional LLD .
The dysplastic hip patient requires detailed preoperative examinations and planning, and the anticipation of a challenging procedure.
This series of articles was created with the support of the following specialists (in alphabetical order):
This issue was created by Word+Vision Media Productions, Switzerland
- Shaw BA, Segal LS. Evaluation and referral for developmental dysplasia of the hip in infants. Pediatrics. 2016 Dec;138(6).
- Committee on Quality Improvement, Subcommittee on Developmental Dysplasia of the Hip. Clinical Practice Guideline: Early Detection of Developmental Dysplasia of the Hip. AAP Policy. 2000 105 (4): 896–905.
- Wikipedia. Hip dysplasia. Available at: https://en.wikipedia.org/wiki/Hip_dysplasia#Acquired. Accessed June 17, 2017.
- Bialik V, Bialik GM, Blazer S, et al. Developmental dysplasia of the hip: a new approach to incidence. Pediatrics. 1999 Jan;103(1):93–99.
- Jacobsen S, Sonne-Holm S. Hip dysplasia: a significant risk factor for the development of hip osteoarthritis. A cross-sectional survey. Rheumatology (Oxford). 2005 Feb;44(2):211–218.
- Yiannakopoulos CK, Chougle A, Eskelinen A, et al. Inter- and intra-observer variability of the Crowe and Hartofilakidis classification systems for congenital hip disease in adults. J Bone Joint Surg Br. 2008 May;90(5):579–583.
- Crowe JF, Mani VJ, Ranawat CS. Total hip replacement in congenital dislocation and dysplasia of the hip. J Bone Joint Surg Am. 1979 61:15–23.
- Hartofilakidis G, Stamos K, Ioannidis TT. Low friction arthroplasty for old untreated congenital dislocation of the hip. J Bone Joint Surg Br. 1988 70:182–186.
- Brunner A, Ulmar B, Reichel H, et al. The Eftekhar and Kerboul classifications in assessment of developmental dysplasia of the hip in adult patients. Measurement of inter- and intraobserver reliability. HSS J. 2008 Feb;4(1):25–31.
- Korkmaz O, Malkoç M. In: Spasovski D, ed. Total Hip Replacement in Developmental Dysplasia of the Hip: Pitfalls and Challenges, Developmental Diseases of the Hip - Diagnosis and Management. 2017. InTech, DOI: 10.5772/67479. Available from: https://www.intechopen.com/books/developmental-diseases-of-the-hip-diagnosis-and-management/total-hip-replacement-in-developmental-dysplasia-of-the-hip-pitfalls-and-challenges .
- Benjamin B. Management of limb length problems during total hip replacement for patients with developmental dysplasia of hip. (Publication pending).
- Krueger C. Adult Dysplasia of Hip. OrthoBullets. Available at: http://www.orthobullets.com/recon/5008/adult-dysplasia-of-the-hip. Accessed June 17, 2017.
- Chu YM, Zhou YX, Han N, et al. Two Different Total Hip Arthroplasties for Hartofilakidis Type C1 Developmental Dysplasia of Hip in Adults. Chin Med J (Engl). 2016 Feb 5;129(3):289–294.
- Dapuzzo R, Sierra RJ. Acetabular considerations during total hip arthroplasty for hip dysplasia. Orthop Clin North Am. 2012 Jul;43(3):369-75.
- Boisgard S, Descamps S, Bouillet B. Complex primary total hip arthroplasty. Orthop Traumatol Surg Res. 2013 Feb;99(1 Suppl):S34–42.
- International Hip Dysplasia Institute. Hip Joint Replacement Surgery for Hip Dysplasia. Available at: http://hipdysplasia.org/adult-hip-dysplasia/adult-treatments/hip-joint-replacement-surgery-for-hip-dysplasia/. Accessed June 17, 2017.
- Argenson JN, Flecher X, Parratte S, et al. Anatomy of the dysplastic hip and consequences for total hip arthroplasty. Clin Orthop Relat Res. 2007;465:40–45.
- Liu R, Liang J, Wang K, et al. Sciatic nerve course in adult patients with unilateral developmental dysplasia of the hip: implications for hip surgery. BMC Surg. 2015;31;15(1):1.
- Lewallen DG. Neurovascular injury associated with hip arthroplasty. Instr Course Lect. 1998;47:275–283.
- Meermans G, Malik A, Johan Witt, et al. Preoperative radiographic assessment of limb-length discrepancy in total hip arthroplasty. Clin Orthop Relat Res. 2011 Jun; 469(6): 1677–1682.
- Charnley J. The long-term results of low-friction arthroplasty of the hip performed as a primary intervention. 1972. Clin Orthop Relat Res. 1995 Oct;(319):4–15.
- Bao N, Meng J, Zhou L, et al. Lesser trochanteric osteotomy in total hip arthroplasty for treating CROWE type IV developmental dysplasia of hip. Int Orthop. 2013 Mar;37(3):385–390.
- Reikeraas O, Lereim P, Gabor I, et al. Femoral shortening in total arthroplasty for completely dislocated hips: 3-7 year results in 25 cases. Acta Orthop Scand. 1996 Feb;67(1):33–36.
- Sener N, Tözün IR, Aşik M. Femoral shortening and cementless arthroplasty in high congenital dislocation of the hip. J Arthroplasty. 2002 Jan;17(1):41–48.
- Neumann D, Thaler C, Dorn U. Femoral shortening and cementless arthroplasty in Crowe type 4 congenital dislocation of the hip. Int Orthop. 2012 Mar;36(3):499–503.
- Koulouvaris P, Stafylas K, Sculco T, et al. Distal femoral shortening in total hip arthroplasty for complex primary hip reconstruction. A new surgical technique. J Arthroplasty. 2008 Oct;23(7):992–998.
- Yoon PW, Kim JI, Kim DO, et al. Cementless Total Hip Arthroplasty for Patients with Crowe Type III or IV Developmental Dysplasia of the Hip: Two-Stage Total Hip Arthroplasty Following Skeletal Traction after Soft Tissue Release for Irreducible Hips. Clin Orthop Surg. 2013 Sep; 5(3): 167–173. Available at: https://www.e-sciencecentral.org/articles/SC000004506. Accessed June 18, 2017.
- Charity JA, Tsiridis E, Sheeraz A, et al. Treatment of Crowe IV high hip dysplasia with total hip replacement using the Exeter stem and shortening derotational subtrochanteric osteotomy. J Bone Joint Surg Br. 2011 Jan;93(1):34–38.
- Pietrzak J. Management of limb length discrepancy after total hip arthroplasty. (Publication pending).