Kirners deformity - a systematic review and surgery recommendations.

Area of Science:

• Orthopedics
• Pediatric Surgery
• Hand Surgery

Background:

• Kirner deformity is a rare adolescent little finger anomaly characterized by distal phalanx abnormalities and L-shaped epiphysis.
• Systematic reviews are lacking due to the condition's rarity, necessitating an overview of its clinical aspects and treatments.

Approach:

• Presents five surgical cases of Kirner deformity treated with flexor digitorum profundus (FDP) tendon partial tenotomy and, in one case, dorsal epiphysiodesis.
• Conducts a systematic literature review to summarize prevalence, epidemiological data, and surgical treatment options for Kirner deformity.

Key Points:

• Kirner deformity affects females more than males (63% vs. 36%) with an average age of presentation at 9.36 years.
• The deformity is frequently bilateral (over 50% of cases).
• Surgical intervention (FDP detachment or osteotomy) is performed in only 7.4% of cases, with over 90% receiving conservative treatment.

Conclusions:

• Surgical detachment of the FDP tendon is recommended for Kirner deformity with functional limitations or pain.
• Conservative therapy with corrective splinting is suitable for incidental findings without functional impairment.
• Early surgical treatment before age 12 enhances long-term functional and aesthetic results.