Working Diagnosis:
Dysplasia Epiphysealis Hemimelica (DEH), or Trevor's Disease

Treatment:
The patient was referred to Pediatric Orthopedic Surgery and she underwent an excision of the left knee intra-articular osteochondroma and lateral femoral condyle with microfracture. She was placed in a hinged knee brace following the surgery, and she was told to wear the brace and remain non-weight bearing for the next 4-weeks until her follow-up visit with the surgeon. She also started physical therapy 2-weeks post-operatively.

Outcome:
The patient missed her 4-week follow-up appointment but did follow-up at 7-weeks post-operatively with the Orthopedic Surgeon. Repeat x-rays were obtained that showed slightly abnormal contour of lateral femoral condyle consistent with removal of intraarticular osteochondroma. There was normal alignment and joint spaces were maintained. The knee brace was discontinued at this visit and she was able to begin weight bearing as tolerated. She was also cleared to start swimming and cycling at this visit. She went back for one more follow-up at 9-weeks post-operatively, at which point she felt confident enough to return to working at the movie theater. She was discharged from physical therapy after a total of 11-weeks. She was lost to follow-up with the surgeon after the 9-week visit, so it was assumed she was doing well given her physical therapy discharge.

Author's Comments:
Trevor's Disease is a rare congenital bone abnormality characterized by asymmetric overgrowth of cartilage within the epiphysis of bones, usually the ankle or knee. Males are affected three times more than females and the incidence is 1:1,000,000. Presentation typically occurs before the age of 8, but has been identified in patients up to 40 years of age. This patient has a particularly rare presentation due to the acute onset, the location and the gender predilection that typically favors males over females. This patient also has localized Trevor's disease, which is more uncommon than the classic presentation which involves more than one epiphysis.

Surgical excision is the preferred method of treatment especially in patients with moderate to severe symptoms, although observation can be recommended for those who do not want surgery.

Editor's Comments:
DEH usually presents as a painless mass of swelling on the side of the affected joint, and pain usually occurs later in the course of the disease. Other symptoms include decreased range of motion, joint deformity, limb length discrepancy and muscle wasting in the affected area. The current patient's only reported symptoms were pain and knee swelling. It is possible that the disease process had been ongoing for several years and had finally gotten to the point of causing constant pain. Her history of genu varum that required bracing at a young age could have been related to her DEH as most cases are diagnosed before 8-years old, and the angular deformities in the knee when the projecting mass distorts the articular surface can present as valgus or varus knee deformity. It would be interesting to know if she obtained imaging or a work-up for her genu varum prior to bracing.

The approach to treatment of DEH differs between surgeons, but usually requires surgical removal of the osteocartilaginois lesion, especially when the lesion is painful or associated with joint abnormalities. Conservative treatment in early asymptomatic lesions is preferred by some surgeons in order to prevent any damage to the joint surface. However, some surgeons will resect the lesion early, even in asymptomatic children, in order to prevent later joint complications. Additionally, the lesions can enlarge with skeletal growth and ossify to underlying bone at maturation making it more desirable to remove the lesion early.

References:
Dysplasia epiphysealis hemimelica rarediseases.org/rare-diseases/dysplasia-epiphysealis-hemimelica/ synonyms of dysplasia epiphysealis hemimelica.

Gokkus K, Murat S, Aydn AT. Comment on the article 'Dysplasia epiphysealis hemimelica of the knee: an unusual presentation with intra-articular loose bodies and literature review' by Wheeldon and Altiok. J Pediatr Orthop B. 2015;24(4):377-378.

Wheeldon G, Altiok H. Dysplasia epiphysealis hemimelica of the knee: an unusual presentation with intra-articular loose bodies and literature review. J Pediatr Orthop B. 2015;24(4):326-329.

Jones, Jeremy. Dysplasia Epiphysealis Hemimelica Radiology Reference Article. Radiopaedia Blog RSS, Radiopaedia.org, 1 Oct. 2021,

Lipman, Rachel MSN, CPNP; John, Rita Marie EdD, DNP, CPNP, PMHS A review of knee pain in adolescent females, The Nurse Practitioner: July 15, 2015 - Volume 40 - Issue 7 - p 28-36,doi: 10.1097/01.NPR.0000466496.11555.ec

Nguyen AD, Boling MC, Levine B, Shultz SJ. Relationships between lower extremity alignment and the quadriceps angle. Clin J Sport Med. 2009 19 3 201 to 206.

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