Below Knee Amputation

Overview on Indication for Below Knee Amputation

By Muhamad Na’im B. Ab Razak

University Science Malaysia

This patient undergone right BKA due to severe lower limb injury and now presented with infected stump site. Arrow shows protrusion of bone.

This patient initially undergone right below knee amputation of the leg due to tumors of the distal leg however requires above knee amputation due to infected stump.

Lower-limb amputation was first performed as a form of punishment during the Hammurabi era in Babylon. It was subsequently recommended by Hippocrates in Greece as treatment for vascular gangrene [JMP de Godoy et al]. It is the most common procedures to be performed as compared to other limb amputation. According to a three years retrospective study by Hazmy W et al in Seremban Hospital, lower limb amputations were performed in 97.5% out of 204 patients with Below Knee Amputation (BKA) is the commonest procedures involving 72% of the cases. The tree main risk factors for major limb amputation are diabetes mellitus, male gender and road traffic accident.

BKA is indicated in cases of benign and malignant tumor of the foot, peripheral vascular disease (PVD), severe traumatic injury of the lower limb with compromise neurovascular status especially involving tibia bone and various complication of diabetic foot like soft tissue necrosis, osteomyelitis, uncontrollable infection, or intractable pain.

BKA is best done in the middle third of the leg as it will gives stump of 5 1/2 to 7 inch below the knee joint and it has good circulation as compared to lower third of the leg. A very short stump may increase the possibility of the re amputation to the above knee joint. [Henry E. loon]

Currently in HUSM, most of the cases resulting from benign and malignant tumor, PVD and open grade IIIC fracture have successfully being managed with limb sparing procedures.

High-grade soft-tissue sarcomas of the lower limb especially at the ankle region is now be managed with multimodality approach as amputation did not offer survival advantages to the patient especially if histopathological changes suggestive of high grade malignancy. Therefore, it can be managed with pre operative adjuvant radiotherapy followed with wide or radical surgical excision plus free tissue transfer flap and adjuvant chemotherapy post operatively.

Severe tibial fracture with neurovascular injury might be considered as indication for amputation as it is more economical and more functional to the patient in the long term. Furthermore, management for open fracture is expensive, time consuming and patient is considered as non-functional or disabled during treatment period. However, a balanced in medical justification is needed before going for primary amputation due to emotional and medico legal aspect. [AS Halim]

It is noted from a retrospective study made by Yusof M I et al, a total of 203 patients have undergone limb amputation in HUSM from July 2003 to June 2005 with 44 cases are decided for below knee amputation. Of all the BKA cases, 94% of the surgery involves diabetic patients, and 2% of patients each had PVD, trauma and tumor.

Therefore, complication of DM is mainly a major indication for BKA. Among the factors contributing to amputation in diabetic patients in Kelantan are 1) lack of knowledge, attitude and practice on DM leading to poor diet and drugs compliance and 2) difficult access to medical facility because of living in rural area [Yusof M I]

Severe necrotizing fasciitis, although rare entity contributing to below knee amputation requires high index of suspiciousness and be treated aggressively as it is also a life threatening orthopedic emergency. All dead and infected tissue must be removed and amputation should be considered if aggressive debridement and excision is not beneficial for limbs.

Other rare case of BKA reported in literature includes osteomyleitis of the right foot secondary to disseminated infection of chronic granulomatous fungal disease caused by Rhinosporidiosis seeberi. This disease primarily affects the nose and mucocutaneous tissue. Dissemination is mainly through hematogenous spread.

Complication of BKA mainly related to the problem with stump either due to breakdown, poor prosthetic fit or both. Infected stump is also possible and may proceed with osteomyelitis or non union, therefore requiring above knee amputation within two to fourteen months. Apart from that, pain at the stump and psychologically distress is also common.

Reference

1) AM Leow, AS Halim & Z Wan, "Reconstructive treatment following resection of high-grade soft-tissue sarcomas of the lower limb", Journal of Orthopaedic Surgery 2005; 13(1):58-63.

2) AS Halim & I Yusof, "Composite vascularised osteocutaneous fibula and sural nerve graft for severe open tibial fracture—functional outcome at one year: A case report", Journal of Orthopaedic Surgery 2004; 12(1):110–113.

3) GM Georgiadis, FF Behrens, MJ Joyce et al, "Open tibial fractures with severe soft-tissue loss. Limb salvage compared with below-the-knee amputation", J Bone Joint Surg Am. 1993; 75:1431-1441.

4) Hazmy W, Mahamud M, Ashikin N et al, "Major limb amputations in Seremban Hospital: a review of 204 cases from 1997-1999", Med J Malaysia. 2001 Jun; 56 Suppl C: 3-7, Medline.

5) Henry E. Loon, "Below-Knee Amputation Surgery", Artificial Limbs: A Review of Current Developments (1962), Vol 6: Number 2.

6) JC Theis, J Rietveld & T Danesh-Clough, "Severe necrotising soft tissue infections in orthopaedic surgery", Journal of Orthopaedic Surgery 2002: 10(2): 108–113.

7) JMP de Godoy, MF de Godoy, F Batigalia et al, "Lower-extremity amputation: A 6-year follow up study in Brazil", Journal of Orthopaedic Surgery 2005; 13(2):164-166.

8) R Amritanand, M Nithyananth, VM Cherian et al, "Disseminated rhinosporidiosis destroying the talus: a case report", Journal of Orthopaedic Surgery 2008; 16(1):99-101.

9) Yusof M I, Sulaiman A R & Muslim D A J, "Diabetic foot complications: a two-year review of limb amputation in a Kelantanese population", Singapore Med J 2007; 48(8):729.