Table 4.
Postoperative complications
| Error | Clinical effect | Prevention | Detection | Remedy |
|---|---|---|---|---|
| Recurrence of deformity [4] | Major complication leading to recurrence of pain. Long-term studies indicate that clinical success deteriorates with time, with continued efficacy in approximately 60% of patients at 10 years followup. | Overcorrection of angular deformity. Coventry et al. showed the risk of failure was increased if alignment was not overcorrected to at least 8o valgus [4] | Careful intraoperative measurements. However, the true alignment under weightbearing conditions will not be known until postoperatively. Standing, full-length radiographs should be performed 6-8 weeks postoperatively. | Revision osteotomy, total arthroplasty, bracing. |
| DVT/PE | Rate of DVT after osteotomy has been reported to be as much as that of TKA. Fatal pulmonary embolism is rare but has been reported | DVT prophylaxis (ie, early ambulation, compression stockings, chemical prophylaxis) | Heightened postoperative clinical suspicion, close monitoring of vital signs, CT or V/Q scan of chest to rule out pulmonary embolism. | Chemical anticoagulation (ie, heparin, Lovenox®, Coumadin®), IVC filter. |
| Compartment syndrome | Exact incidence unknown, however elevated anterior compartment pressures are common after HTO. Risk may be increased when concomitant, arthroscopically assisted ligament reconstruction is performed. | Careful surgical technique can avoid possible trauma and vascular injury that may lead to a compartment syndrome. Avoid prolonged postoperative epidural analgesia that potentially could mask compartment syndrome. | Tense compartments, pain with passive stretch, elevated compartment pressures, pain out of proportion, increasing pain medication requirement. | If compartment syndrome is suspected, then a fasciotomy should be performed immediately. |
| Patella baja [9] | HTO has been associated with a high incidence of patella baja. Can result in anterior knee pain and more difficult conversion to TKA. Lateral closing wedge HTO results in baja because of a contracture of the patellar ligament after prolonged immobilization, whereas a medial opening wedge actually increases the tibiofemoral joint line. | Patellar tendon contracture after a lateral closing wedge HTO can be eliminated by using rigid internal fixation and aggressive postoperative mobilization, rather than prolonged casting. | Physical examination, radiographs | Revision, total arthroplasty |
| Osteonecrosis of the proximal fragment | Osteonecrosis of the proximal tibial fragment can result if the bone segment is cut too thin, or if a fracture propagates from the osteotomy site creating a detached bony island. Both can compromise blood supply to the proximal fragment. | Must leave a proximal fragment of at least 15 mm thickness and minimize the risk of intraarticular and far cortex fractures. Carry the apex of the osteotomy cut to within 10 mm of the far cortex, and the addition of a drill hole at the apex of the osteotomy site can increase the amount of correction obtained before cortical fracture. | Postoperative pain, physical examination, radiographs (sclerosis, deformity, collapse) | Bone grafting, revision osteotomy, total arthroplasty |
| Infections | Most common with medial opening wedge techniques that involve use of external fixator. Although external fixators allow for more precise angular correction, superficial pin tract infections are common (25%-50%). More serious infections, although rare, include septic arthritis and chronic osteomyelitis, which may jeopardize subsequent salvage with TKA. | Strict adherence to sterile operative technique, with the use of prophylactic perioperative antibiotics. Diligent postoperative pin care. Avoidance of external fixators for medial opening wedge HTO, in favor of a medial distraction plate. | ESR, CRP, WBC, fevers, erythema, warmth, swelling, positive cultures | Pin tract infections typically remain superficial and respond favorably to pin care and oral antibiotics. Deeper infections may require thorough washout and débridement. |
| Delayed union and nonunion | Rare occurrence that is associated with motion between the osteotomy fragments. Less common after lateral closing wedge HTO because of excellent healing potential of two metaphyseal cancellous surfaces that are in direct apposition. Medial opening wedge techniques, however, must traverse segment of the autograft or allograft. | Rigid fixation of osteotomy fragments in a biologically healthy environment will decrease the chance of nonunion. Large angular corrections are relative contraindications to medial distraction plate technique because of risk of nonunion. Avoid patient risk factors, such as tobacco use and diabetes mellitus. | Physical examination, radiographs | Resection of the pseudarthrosis, bone grafting, and rigid fixation |
| Peroneal nerve palsy [7] | Most often related to fibular osteotomy in conjunction with lateral closing wedge HTO. Incidence has been reported as much as 20%. Postoperative peroneal deficits also may be related to increased pressure in the anterior compartment. | Care must be taken when dissecting and retracting in the vicinity of the fibular head. Use blunt retractor to protect the neurovascular structures when dissecting around the tibiofibular capsule. | Careful postoperative neurologic examination, close monitoring for potential compartment syndrome. | Conservative management, bracing |
| TKA after osteotomy [10] | After 10 years, 40% of patients require conversion to TKA. More technically demanding procedure with slightly lower rates of excellent results. Contracture of the patellar tendon (patella baja), prior skin incisions, retained hardware, large angular corrections, and diminished tibial bone stock all can complicate subsequent TKA. | Careful attention to preserving tibial bone stock, early mobilization to prevent patellar tendon contracture, and use of a standard midline longitudinal incision can make conversion to an eventual TKA easier. | Physical examination, radiographs | Avoidance of thin skin bridges (< 7 cm), removal of retained hardware, careful consideration of proximal tibial deformation in preoperative TKA planning, and possible modified/revision of components for large angular corrections |
HTO = high tibial osteotomy; IVC = inferior vena cava; V/Q = ventilation/perfusion; ESR = erythrocyte sedimentation rate; CRP = C-reactive protein; WBC = white blood cell; Lovenox®, Sanofi US, Bridgewater, NJ, USA; Coumadin®, Bristol-Myers Squibb, Bridgewater, NJ, USA.