lower extremity

A 55-year-old man is evaluated in the emergency department for foot salvage after he was involved in a motorcycle collision. Flow is restored after 6 hours from the time of injury. On examination, the foot is cold, and no plantar sensation is noted. The posterior tibial nerve is disrupted. A temporary external fixator is placed. A photograph and an x-ray study are shown. Which of the following is the most appropriate classification of this injury and recommendation for management?

• Gustilo type IIIB; amputation

• Gustilo type IIIB; reconstruction

• Gustilo type IIIC; amputation

• Gustilo type IIIC; reconstruction

Answer explanation

The correct response is Option C.

The patient described has a Gustilo IIIC injury. Based on the best available data, he should undergo amputation.

Ultimately, the choice to reconstruct versus amputate is a gestalt of the situation and the patient, as well as the capabilities of the hospital and the care team. In this case, the factors influencing the decision would be the warm ischemia time of 6 hours and severed posterior tibial nerve, as well as the extensive soft-tissue injury.

Some of the newer data suggests that absence of plantar sensation is no longer criteria for amputation in and of itself. However, an anatomically disrupted nerve in an adult strongly favors amputation.

In addition, there is evidence supporting the notion that limb salvage might involve less cost in the long term versus reconstruction.

Gustilo Classification

I: open fracture; clean; wound less than 1 cm

II: open fracture; wound greater than 1 cm

IIIA: open fracture; extensive soft-tissue injury but adequate tissue for coverage

IIIB: open fracture; extensive soft-tissue injury but inadequate tissue for coverage

IIIC: any of the above with a vascular (arterial) injury

References

1. Chung KC, Saddawi-Konefka D, Haase SC, et al. A cost-utility analysis of amputation versus salvage for Gustilo type IIIB and IIIC open tibial fractures. Plast Reconstr Surg. 2009 Dec;124(6):1965-1973.

2. Higgins TF, Klatt JB, Beals TC. Lower Extremity Assessment Project (LEAP)—the best available evidence on limb-threatening lower extremity trauma. Orthop Clin North Am. 2010 Apr;41(2):233-239.

3. Jacobs C, Siozos P, Raible C, et al. Amputation of a lower extremity after severe trauma. Oper Orthop Traumatol. 2011 Oct;23(4):306-317.

4. MacKenzie EJ, Bosse MJ. Factors influencing outcome following limb-threatening lower limb trauma: lessons learned from the Lower Extremity Assessment Project (LEAP). J Am Acad Orthop Surg. 2006;14(10 Spec No.):S205-210.

5. Russell WL, Sailors DM, Whittle TB, et al. Limb salvage versus traumatic amputation. A decision based on a seven-part predictive index. Ann Surg. 1991 May;213(5):473-480.

6. Tintle SM, Keeling JJ, Shawen SB, et al. Traumatic and trauma-related amputations: part I: general principles and lower-extremity amputations. J Bone Joint Surg Am. 2010 Dec 1;92(17):2852-2868.

Which of the following compartment pressure measurements is the minimum threshold that is most consistent with compartment syndrome?

• 10 mmHg

• 20 mmHg

• 30 mmHg

• 40 mmHg

• 50 mmHg

Answer explanation

The correct response is Option C.

The absolute minimum compartment pressure measurements ranging from 25 to 50 mmHg are quoted as absolute indications for fasciotomy. The most frequently quoted absolute measurement is 30 mmHg.

References

1. Maser B. Compartment Syndrome. In: Greer SE, Benhaim P, Longaker MT, et al, eds. Handbook of Plastic Surgery. Boca Raton: CRC Press; 2004:417-420.

2. Zamboni WA and Kiraly EM. Compartment Syndrome. In: Achauer BM, Eriksson E, Guyuron B, et al, eds. Plastic Surgery Indications, Operations, and Outcomes. St. Louis, MO: Mosby; 2000:1819-1830.

When a pedicled sural flap is raised to the heel, which of the following is the origin of the arterial blood supply?

• Descending genicular artery

• Lateral sural artery

• Medial femoral circumflex artery

• Medial plantar artery

• Peroneal artery

Answer explanation

The correct response is Option E.

The reverse sural flap is a fasciocutaneous flap often used for ankle or heel wounds. The blood supply of the flap can be from a median superficial artery or the arterial plexus that travels with the sural nerve; the origin is a lower peroneal perforator located approximately 5 cm proximal to the lateral malleolus.

The lateral sural artery would be the appropriate blood supply for perfusion of a pedicled lateral gastrocnemius flap. 

The gracilis flap blood supply derives from the medial circumflex artery. 

The descending genicular artery provides the blood supply of the medial femoral condyle flap. 

The medial plantar artery is the blood supply for the medial plantar artery flap.

References

1. Buluç L, Tosun B, Sen C, Sarlak AY. A modified technique for transposition of the reverse sural artery flap. Plast Reconstr Surg. 2006 Jun;117(7):2488-92.

2. DeFazio MV, Han KD, Attinger CE. Foot reconstruction. In: Song DH, ed. Lower Extremity, Trunk, and Burns. Philadelphia, PA: Elsevier; 2018;184-217. Neligan PC, ed; Plastic Surgery; vol 4.

3. Donegan R, Blume PA. Thirteen year follow-up reverse sural artery flap for plantar calcaneal wound: a case report. J Foot Ankle Surg. 2018 Jul-Aug;57(4):833-837.

4. Wei JW, Dong ZG, Ni JD, et al. Influence of flap factors on partial necrosis of reverse sural artery flap: a study of 179 consecutive flaps. J Trauma Acute Care Surg. 2012 Mar;72(3):744-750.

A 40-year-old man sustains an avulsion of the weight-bearing portion of the medial heel. Coverage with an instep flap is planned. Sensation to this flap is provided by which of the following?

• Lateral plantar nerve from the deep peroneal nerve

• Lateral plantar nerve from the superficial peroneal nerve

• Lateral plantar nerve from the sural nerve

• Medial plantar nerve from the deep peroneal nerve

• Medial plantar nerve from the tibial nerve

Answer explanation

The correct response is Option E.

The medial plantar artery flap, or instep flap, provides sensate, full-thickness glabrous skin and subcutaneous tissue that can be transferred as a pedicled or free flap. The tissue is well suited for weight-bearing areas of the foot but has also been used as a free tissue transfer for palmar defects. Because the instep donor site is non-weight-bearing, the donor site can be covered with a skin graft. The innervation of the medial instep flap comes from the medial plantar nerve, a branch of the tibial nerve.

References

Mourougayan V. Medial plantar artery (instep flap) flap. Ann Plast Surg. 2006 Feb;56(2):160-3.

Scheufler O, Kalbermatten D, Pierer G. Instep free flap for plantar soft tissue reconstruction: indications and options. Microsurgery. 2007;27(3):174-80.

Wan DC, Gabbay J, Levi B, Boyd JB, Granzow JW. Quality of innervation in sensate medial plantar flaps for heel reconstruction. Plast Reconstr Surg. 2011 Feb;127(2):723-30.

A 50-year-old man comes to the office because of a persistent nonhealing wound 6 months after he underwent open reduction and internal fixation of an open ankle fracture. Examination shows palpable pedal pulse with retained protective sensation of the foot. Which of the following is the most appropriate initial step in management of this patient?

• Application of collagenase ointment

• Core needle bone culture

• Coverage with a free flap

• Operative debridement

• Referral for hyperbaric oxygen therapy

Answer explanation

The correct response is Option D.

The patient is at high risk for fracture nonunion and osteomyelitis. The best next course of management is operative debridement ideally along with the treating orthopedist to make judgments about bone viability and debridement and the risks and benefits of hardware removal. Enzymatic wound debridement would not address the concerns about the deeper wound issues. The role for hyperbaric oxygen in the scenario presented is not well established. Bone cultures at the time of operative debridement should be obtained; but, percutaneous core needle cultures alone would not likely be adequate to obtain best healing. Free flap coverage may be required but is not indicated at this time.

References

Anghel EL, DeFazio MV, Barker JC, et al. Current Concepts in Debridement: Science and Strategies. Plast Reconstr Surg. 2016 Sep;138(3 Suppl):82S-93S.

Cierny G 3rd. Surgical treatment of osteomyelitis. Plast Reconstr Surg. 2011 Jan;127 Suppl 1:190S-204S.

A 62-year-old man is brought to the emergency department by helicopter after sustaining severe injuries to the head, neck, and right femur during a motor vehicle collision. The patient's condition is stabilized, and the femur is temporarily reduced and splint immobilized. Peripheral pulses in the right leg are not palpable and capillary refill is noted; handheld Doppler shows weak pulses. Which of the following is the most appropriate next step to establish lower extremity vascular injury in this patient?

• CT angiography

• Doppler ultrasonography

• Measurement of ankle brachial index

• Serial physical examinations

Answer explanation

The correct response is Option A.

As with many patients who have sustained severe upper or lower extremity trauma, the vascular status of the limb in the patient described is in question. Because of significant collateral blood flow in the upper and lower extremities, capillary refill and handheld Doppler tones can often be found even with complete disruption of major arteries. Although traditional angiography is known as the ?gold standard? for the diagnosis of vascular injuries, it is not without its difficulties. A special suite, technicians, and physicians are needed to perform traditional angiography, and the potential for morbidity has been noted. As a result, CT angiography is fast becoming the new ?gold standard? for the diagnosis of vascular injuries. Coupled with the fact that many trauma patients will be brought to the CT suite for other injuries, CT angiography is a rapid and natural next step to be taken when the head or abdomen is being scanned. Serial physical examination, ankle brachial index, and Doppler ultrasonography are adequate techniques, but they may be operator-dependent or sometimes have difficulty localizing the actual injury. Both traditional and CT angiography will localize the injury, but, for obvious reasons, CT angiography has overtaken traditional angiography in the diagnosis of acute vascular injury in the trauma patient.

References

Bravman JT, Ipaktchi K, Biffl WL, et al. Vascular injuries after minor blunt upper extremity trauma: pitfalls in the recognition and diagnosis of potential "near miss" injuries. Scand J Trauma Resusc Emerg Med. 2008 Nov 25;16(1):16.

Redmond JM, Levy BA, Dajani KA, et al. Detecting vascular injury in lower-extremity orthopedic trauma: the role of CT angiography. Orthopedics. 2008 Aug;31(8):761-767.

A 57-year-old man comes to the office 4 weeks after undergoing a free osseocutaneous fibula flap. He says he has pain with walking. A photograph is shown. X-ray studies show 6 cm of fibular bone remains proximally and distally. Sensation of the right foot shows no abnormalities; pain is noted on plantar flexion. Which of the following is the most appropriate next step in management?

• Cast immobilization of the lower extremity (above the knee)

• Cast immobilization of the lower extremity (below the knee)

• Operative exploration and bone grafting

• Operative exploration and nerve grafting

• Reassurance that the pain is self-limiting

Answer explanation

The correct response is Option E.

Vascularized bone flap is typically needed for defects >6 cm regardless of location in the body. The fibula is a common donor for vascularized bone. Understanding the postoperative course and complications is needed both in terms of discussions with the patient preoperatively and management of the patient’s condition after surgery. Common sequelae of fibula harvest include pain in the leg (especially when walking). Four weeks is relatively early in the postoperative course and reassurance should be given.

Risks of fibula harvest include damage to the peroneal nerve (increased when <6 cm of bone is left behind or when the head of the fibula is included in the harvest); destabilization of the ankle (increased when <6 cm of bone is left behind); and damage to the posterior tibial nerve.

A free-fibular flap design with hash marks left intact is shown.

References

1. Lee JH, Chung CY, Myoung H, et al. Gait analysis of donor leg after free fibular flap transfer. Int J Oral Maxillofac Surg. 2008 Jul;37(7):625-629.

2. Sieg P, Taner C, Hakim SG, et al. Long-term evaluation of donor site morbidity after free fibula transfer. Br J Oral Maxillofac Surg. 2010 Jun;48(4):267-270.

3. Salgado CJ, Moran SL, Mardini S, et al. Fibula flap. In: Wei FC, Mardini S, eds. Flaps and Reconstructive Surgery. 1st ed. Philadelphia, PA: Saunders; 2009:439-456.

A 63-year-old man presents to the office with a 4 × 4-cm heel defect. A local podiatrist has debrided the calcaneus, and there is healthy granulation tissue present. After extensive discussion with the patient, it is decided to proceed with a distally based sural fasciocutaneous flap for coverage. Which of the following risk factors is associated with the highest rate of flap-related complications?

• Coronary artery disease

• Diabetes mellitus

• Hypertension

• Obesity

• Venous insufficiency

Answer explanation

The correct response is Option E.

A recent meta-analysis of 61 papers showed that venous insufficiency is associated with a nine-fold increase in risk of developing a complication in a distally based sural flap. Other risk factors, such as peripheral vascular disease, diabetes, obesity, and hypertension, have been associated with increased rates of complications previously in the literature, but venous insufficiency is associated with the highest rate of complications. The pooled data from this series showed a 26% complication rate, a 3.2% flap loss rate, and a 15.3% partial flap loss rate. As the design of the sural flap is distally based, the physiology of the flap requires reversed flow through the venous system.

Advanced age is also associated with an increased complication rate and there is literature to suggest a delay procedure in this patient population. Other papers have found smoking to have a higher risk of complications as well. There is still much debate over which patients should undergo a delay procedure or venous supercharging, but in general, high-risk patients with multiple comorbidities should be considered for this additional surgery. Coronary artery disease has not been found to be associated with increased risk of flap-related complications.

References

1. de Blacam C, Colakoglu S, Ogunleye AA, et al. Risk factors associated with complications in lower-extremity reconstruction with the distally based sural flap: a systematic review and pooled analysis. J Plast Reconstr Aesthet Surg. 2014 May;67(5):607-616.

2. Follmar KE, Baccarani A, Baumeister SP, et al. The distally based sural flap. Plast Reconstr Surg. 2007 May;119(6):138e-148e.

3. Parrett BM, Pribaz JJ, Matros E, et al. Risk analysis for the reverse sural fasciocutaneous flap in distal leg reconstruction. Plast Reconstr Surg. 2009 May;123(5):1499-1504.

A 25-year-old man is brought to the emergency department with a large degloving injury with exposed tibia and ankle joint (Gustilo Type IIIB) sustained during a motorcycle collision. After multiple debridements, the plastic surgeon is consulted 6 days later. Routine laboratory testing shows a platelet count of 1.5 million/mL, increased from normal range on admission. Free flap reconstruction is planned. Which of the following is the most appropriate next step in management in this patient?

• Consult hematology for bone marrow biopsy

• Delay reconstruction until platelet count is within normal range

• Initiate antiplatelet therapy

• Proceed with free tissue transfer

Answer explanation

The correct response is Option C.

Antiplatelet therapy should be initiated to minimize the risk for flap loss in this patient. This patient has a reactive thrombocytosis which can commonly occur following trauma, infection, inflammation, or major surgery (e.g., post-splenectomy). This temporary elevation in platelet count is usually transient and peaks at approximately 2 weeks after injury. The traditional pharmacologic agents for microvascular thrombosis have minimal (e.g., aspirin) or no anti-platelet effects (e.g., heparin, hirudin, and thrombolytic agents). There are no guidelines or standards of care, but Hollenbeck et al. advocate for administration of glycoprotein IIb/IIIa antagonists (e.g., abciximab, tirofiban, and eptifibatide), which block the final common pathway for platelet aggregation. Thienopyridines (e.g., clopidogrel) often reach steady state after 4 to 7 days, which would further delay surgery. Platelet apheresis has also been described to reduce platelet count and secondary flap salvage.

Acute trauma patients with elevated preoperative platelet counts are at higher risk for both intraoperative and postoperative microvascular complications (especially arterial thrombosis). Proceeding with free tissue transfer without any precautions is high risk for failure.

A hematology consult and bone marrow biopsy is not necessary since the hypercoagulable state is usually self-limited but can take several weeks. This is not a chronic medical condition requiring further workup or treatment.

Multiple studies suggest that patients with complex open fractures requiring soft-tissue coverage have improved outcomes with early free flap coverage, so it is not appropriate to wait until after this condition resolves. The platelet elevations can peak at approximately 2 weeks, which would delay reconstruction and increase morbidity. Delaying reconstruction increases the risks for infection, nonunion, and ultimately failure of limb salvage.

References

1. Cho EH, Bauder AR, Centkowski S, et al. Preoperative Platelet Count Predicts Lower Extremity Free Flap Thrombosis: A Multi-Institutional Experience. Plast Reconstr Surg. 2017;139(1):220-230.

2. Cho EH, Ligh C, Hodulik KI, et al. Role of platelet inhibition in microvascular surgery. J Reconstr Microsurg. 2014;30:589-598.

3. Choe EI, Kasabian AK, Kolker AR, et al. Thrombocytosis after major lower extremity trauma: mechanism and possible role in free flap failure. Ann Plast Surg. 1996;36:489-494.

4. Tarabishy SP, Inglesby D, Tapp M, et al. Thrombocytosis is associated with complications after microvascular surgery: An NSQIP data analysis. Microsurgery. 2020;40(3):288-297.

A 35-year-old man is brought to the emergency department 2 hours after sustaining a severe crush injury to the right distal thigh in a motor vehicle collision. Physical examination shows an open fracture of the femur; the leg and foot are pale and cool. There are no palpable popliteal, dorsalis pedis, or posterior tibialis pulses. Closed reduction does not restore perfusion. Which of the following is the most appropriate next step?

• Arterial repair with a polytetrafluoroethylene graft

• Arterial repair with reverse saphenous vein graft

• CT angiography

• Intramedullary fixation of the femoral fracture

• Placement of a temporary vascular shunt

Answer explanation

The correct response is Option E.

Gustilo Type IIIC fractures involve arterial injury requiring repair irrespective of the degree of soft tissue and often represent significant limb-threatening injuries. Early recognition and management of lower extremity vascular injury is crucial to limb salvage. CT angiography is of little benefit in the presence of hard signs of vascular injury and can delay operative intervention as well as increase limb ischemia time.

The combination of vascular and orthopedic injuries requiring repair is rare, with a reported incidence as low as 1.5%. Data exist from both wartime and civilian groups evaluating the sequence of management of such injuries. The recommended algorithm suggests improved ischemia times and favorable limb salvage rates with temporary vascular repair, using shunts as the initial adjunct to restore perfusion followed by debridement and fracture fixation.

Definitive vascular repair should follow debridement and fracture fixation. Both synthetic polytetrafluoroethylene and autologous (reverse saphenous vein) interposition grafts are reported to be used in traumatic reconstruction, although autologous tissue is often preferred in the setting of gross contamination.

References

1. Desai P, Audige L, Suk M. Combined orthopedic and vascular lower extremity injuries: sequence of care and outcomes. Am J Orthop. 2012 Apr;41(4):182-186.

2. Glass GE, Pearse MF, Nanchahal J. Improving lower limb salvage following fractures with vascular injury: a systematic review and new management algorithm. J Plast Reconstr Aesthet Surg. 2009 May;62(5):571-579.

3. Percival TJ, Rasmussen TE. Reperfusion strategies in the management of extremity vascular injury with ischaemia. Br J Surg. 2012 Jan;99(Suppl 1):66-74.