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CASE REPORT
Year : 2023 | Volume
: 22
| Issue : 2 | Page : 231-234
Preoperative percutaneous hamstring tenotomy in a patient with severe flexion deformity undergoing primary total knee replacement: Case report and literature review
Mohammed Inuwa Maitama1, Ibrahim Abolaji Alabi2
1 Department of Orthopedic and Trauma Surgery, Ahmadu Bello University, Zaria, Kaduna, Nigeria
2 Department of Clinical Orthopedics, National Orthopedic Hospital, Dala, Kano, Nigeria
Correspondence Address:
Mohammed Inuwa Maitama
Department of Trauma and Orthopedic Surgery, Ahmadu Bello University, Zaria, Kaduna
Nigeria
Source of Support: None, Conflict of Interest: None
CheckDOI: 10.4103/aam.aam_237_21
Abstract
Fixed flexion deformity may accompany severe knee osteoarthritis in patients with long-standing pathology. This makes it difficult to achieve complete knee extension intraoperatively during total knee replacement surgery. Various options of treatment are available including preoperative serial knee extension and casting, intraoperative additional distal femoral resection to increase extension gap, and extensive soft tissue releases. We present this technique of on-table percutaneous medial hamstring tenotomy that we found helpful in achieving complete or near-complete knee extension intraoperatively, thereby minimizing the need for extensive bone resection and soft tissue dissection. An M is a 78-year-old man who presented with inability to walk for a 2-year duration due to pain and deformity of both knees. Complete clinical evaluation revealed the diagnosis of bilateral severe knee osteoarthritis with fixed flexion deformities. Ranges of knee motion were 90°–120° on the right and 80°–125° on the left. On-table percutaneous medial hamstring tenotomy + extension exercise under spinal anesthesia was carried out first and subsequently had posterior stabilized semi-constrained knee replacement. Knee extensions of 160° and 180° were achieved preoperatively after tenotomy and exercise and intraoperatively following distal cuts and soft tissue releases, respectively. This technique may be additive to various attempts at achieving adequate knee extension preoperatively for successful knee replacement. May be further evaluated to assess its effectiveness or otherwise to selected patients with severe flexion contractures undergoing primary total knee replacement.
Abstract in French Résumé
Une déformation en flexion fixe peut accompagner une arthrose sévère du genou chez les patients présentant une pathologie de longue date. Cela rend difficile deobtenir une extension complète du genou en peropératoire lors d'une arthroplastie totale du genou. Diverses options de traitement sont disponibles, y compris extension et moulage préopératoires du genou en série, résection fémorale distale supplémentaire peropératoire pour augmenter l'écart d'extension et extension douce libérations de tissus. Nous présentons cette technique de ténotomie percutanée des ischio-jambiers médiaux sur table que nous avons trouvée utile pour obtenir une ou une extension quasi-complète du genou en peropératoire, minimisant ainsi le besoin d'une résection osseuse étendue et d'une dissection des tissus mous. Un Mest un homme de 78 ans qui s'est présenté avec une incapacité à marcher pendant une durée de 2 ans en raison de douleurs et d'une déformation des deux genoux. Clinique complète l'évaluation a révélé le diagnostic d'arthrose sévère bilatérale du genou avec déformations fixes en flexion. Les amplitudes de mouvement du genou étaient de 90° à 120° à droite et 80°–125° à gauche. Une ténotomie percutanée des ischio-jambiers médiaux sur table + exercice d'extension sous rachianesthésie a été réalisée en premier lieu puis a subi une arthroplastie totale du genou semi-contrainte postérieure stabilisée. Extensions du genou de 160° et 180° ont été réalisées en préopératoire après ténotomie et exercice et en peropératoire après des coupes distales et des libérations de tissus mous, respectivement. Cetechnique peut s'ajouter à diverses tentatives pour obtenir une extension adéquate du genou avant l'opération pour une arthroplastie réussie du genou. Peut être évalué plus avant pour évaluer son efficacité ou autrement chez des patients sélectionnés présentant des contractures sévères en flexion subissant une chirurgie primaire du genou remplacement.
Mots-clés: Contracture en flexion, ténotomie des ischio-jambiers, arthroplastie totale primaire du genou
Keywords: Flexion contracture, hamstring tenotomy, primary total knee replacement
Introduction 
Fixed flexion deformity that accompanies long-standing severe knee osteoarthritis is not uncommon in the West African subregion due to the reluctance of most patients to consent to total knee replacement as a surgical option of treatment in its early stage or inability to afford the expensive procedure. The majority present for treatment when they could not stand or walk due to associated deformity characterized by tightening of posterior capsule and collateral ligaments, osteophytes at posterior femoral condyle and hamstring shortening, making it difficult to achieve soft tissue balancing during total knee arthroplasty (TKA). This is particularly challenging due to the need for achieving complete correction (complete or near-complete knee extension 170°–180°) intraoperatively to facilitate early mobilization, maintain correction gained, and prevent relapse postoperatively as it has been shown that residual flexion contractures after TKA have been associated with poorer functional scores and outcomes[1],[2] This is because standing on flexed knee requires greater quadriceps effort which may result in greater load being transmitted across the joint and increased strain contact forces in the patellofemoral joint with anterior knee pain.
Case Report An M is a 78-year-old man who presented with inability to walk for a 2-year duration due to pain and deformity of both knees. He had multiple sessions of physiotherapy, analgesic, and skeletal muscle relaxants, and other forms of conservative management in various places at various times to no avail. He stopped attending physiotherapy due to increasing pain each time he had knee flexion–extension exercise. He was offered knee replacement surgery 10 years presentation for moderate-to-severe knee arthritis but refused. Complete clinical and radiological evaluation revealed diagnosis of bilateral severe knee osteoarthritis with fixed flexion deformities [Figure 1], [Figure 2], [Figure 3]. The range of knee motion was 90°–120° on the right and 80°–125° on the left [Figure 4]. There were 15° varus deformities bilaterally. He was counseled, optimized, and consented for TKR. On-table percutaneous medial hamstring tenotomy + extension exercise under spinal anesthesia was carried out first [Figure 5] and subsequently had posterior stabilized semi-constrained right total knee replacement [Figure 6] and [Figure 7]. Additional 3 mm distal femoral cut was performed to increase the extension gap, in addition to posterior capsulotomy and osteophytes removal. About 9 mm of proximal tibial cuts was done at minimal slope angle. A thin (10 mm) tibial insert was used to negotiate limited extension space, thereby allowing satisfactory knee extension. One hundred and sixty degree knee extension was achieved preoperatively after tenotomy and exercise. One hundred and eighty degree extension was achieved postoperatively following adequate distal cuts, insertion of thin tibial insert, and soft tissue releases. Wound closed in layers over a redivac drain.
Discussion Performing total knee replacement in advanced knee arthritis is quite challenging due to the difficulty in achieving complete knee extension, a goal that must be achieved for successful outcome. Preoperative physiotherapy in form of serial manipulation and casting is not usually effective due to pain. Parsley et al.[3] have noted that patients with little flexion before surgery tend to gain motion and those having bigger flexion tend to lose it.
We did extraarticular percutaneous tenotomy on the medial hamstring, sparing the lateral tendon so as not to significantly weaken the power for active knee flexion and at the same time allowing for gentle knee extension.
Additional distal femoral cuts may be made to increase the extension gap, but when excessive, can alter the balanced flexion/extension gap ratio leading to widening of flexion gap, cam-post disengagement, and components dislocation. Scuderi and Kochhar[4] have proposed that for every 10° of flexion contracture, 2 mm of additional bone resection may be needed for gap negotiation. However, excessive distal femoral resection alone may lead to superior migration of joint line and abnormally low position of the patella (Baja) which may further reduce quadriceps power affecting joint mechanics. Ilyas et al.[5] have concluded in their study that posterior soft tissue releases and osteophyte resection were more important than additional bone cuts for gap negotiation and extension lag correction.
Therefore, only 3 mm of additional distal femoral bone was removed for the index patient.
Additional bone resection may be carried out on proximal tibia to reduce the overall thickness of resected distal femur minimizing superior migration of joint line; however, caution is to be undertaken for excessive tibial resection when using short or standard tibial stem implants since tibial compressive strength diminishes rapidly with the resection of more than 10 mm of bone, risking loosening, and early failure. Correct placement of femoral and tibial components also plays a role in achieving intraoperative correction of flexion deformity. If femoral component is placed in flexion relative to the femoral axis, full extension will not be achieved due to restraints in arc of motion. On the other hand, decrease in posterior tibial slope may enhance correction.
We resected 9 mm thickness of tibial bone and did adequate soft tissue releases and removal of osteophytes. This has helped in achieving subsequent soft tissue balancing.
He was commenced on gentle knee flexion–extension exercises postoperatively and the limb was casted on the 2nd week. He was placed on antibiotics, analgesics and anticoagulant. The decision to cast the limb on the 2nd week was to help regain quadriceps tone and stand on the limb, as the quadriceps muscle and anterior capsule were stretched and elongated making him have difficulty in achieving full active extension. He was discharged on the 3rd week postoperative to outpatient clinic follow-up.
The plan was made to take the second knee without hamstring tenotomy (as a control) 6 months after the 1st surgery, but the patient died presumably from COVID-19-related complications.
Conclusion We found this technique helpful in lessening the degree of flexion contracture just before surgery complementing preoperative exercise under anesthesia. It may be additive to various attempts at achieving adequate knee extension preoperatively for successful knee replacement. It may further be evaluated to assess its usefulness or otherwise to selected patients with severe flexion contractures undergoing primary total knee replacement.
Limitations
Lack of controlInability to perform the surgery on the second knee, and consequently, lack of effective postoperative patient mobilization to assess the full functional outcome.Despite the above limitations, the strength of our conviction lies in the fact that full correction was achieved with painless appreciable increase in the arc of right knee motion postoperatively.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
References 
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