Advancing Care in Extremity Surgery: Strategies for Neuropathic Pain and Reconstructions of Lower Extremity Defects

The objective of this thesis was to expand knowledge about extremity surgery, focusing on neuropathic pain and lower extremity free flap reconstructions. Chapter 1 introduces the pathophysiology of pain, neuromas, compression neuropathies, and free tissue transplantation, and outlines current challenges.

Part I: Neuropathic Pain in Extremity Surgery
Chapter 2 describes an anatomical study of 18 cadavers examining the infrapatellar branch of the saphenous nerve. Considerable variation was found in origin and course, including multiple branches, which may explain inconsistent outcomes after selective denervation. A more proximal diagnostic nerve block is suggested to improve patient selection.

Chapters 3 and 4 present systematic reviews and meta-analyses on residual limb pain (RLP) and symptomatic neuroma after amputations. After upper extremity amputation, pooled prevalence was 58% for RLP and 22% for neuroma. After lower extremity amputation, pooled prevalence was 59% and 15%, respectively. Higher RLP rates were associated with older age, longer follow-up, and certain data collection methods, emphasizing the need for awareness and prevention.

Chapter 5 evaluates extensive neurolysis with free gracilis muscle flap coverage for therapy-resistant ulnar nerve pain. In 18 patients with follow-up, pain scores decreased and pain medication use declined. This approach offers an option when prior surgeries fail.

Part II: New Perspectives on Free Flap Reconstructions
Chapters 6 and 7 compare fasciocutaneous and muscle flaps in a multicenter cohort. No significant differences were found in function, quality of life, aesthetics, or social impact. Poorer outcomes were associated with pain, obesity, diabetes, reduced mental health, and shorter follow-up. Flap choice should depend on defect characteristics and surgeon preference, considering patient factors.

Chapter 8 presents a randomized controlled trial on the “dangling” protocol after lower extremity free flap reconstruction. Unrestricted mobilization after seven days was non-inferior to gradual exposure in terms of partial flap loss. Surgeons and patients do not need to follow a dangling protocol restricting early dangling and therefore restricting early mobilization. Further research is needed to determine whether eliminating dangling protocols even earlier in the recovery process is safe, which could potentially shorten hospital stays and reduce resource use.