Humeral Shaft Nonunion

Humeral shaft fractures treated with hanging casts or coaptation splints (U-slabs) can lead to nonunions, often of the oligotrophic type—particularly in the elderly and those with obese, flabby arms—or a true synovial pseudarthrosis, forming a “second shoulder” (Fig. 41.2).

These nonunions need rigid ORIF with a dynamic compression plate (DCP) or locked IM nail, usually with bone graft, and most commonly through an anterolateral approach, or if the radial nerve needs exploration, a posterior approach. Bone ends are resected to bleeding bone and the medullary canals opened. Shortening up to 3 cm is well tolerated. A second plate can be added in the face of osteoporosis.

Radial and Ulnar Nonunion

Non-operative management of both bone forearm fractures or inadequate surgical fixation with Steinmann pins or K-wires as “alignment rods” often leads to nonunion of one or both bones. No surgery is needed if one bone is healed, hand and elbow function are normal, and pro-supination is painless, but this is rarely the case. Rigid internal fixation of both bones with plates and screws, along with iliac crest bone graft that allows early mobilization, is the best option. Shortening up to 2 cm is acceptable, with both bones shortened the same amount. Re-establish the normal bow of the radius to maximize forearm pro-supination.

Nonunion of the distal radius and ulna is less common and, if symptomatic, should be taken down to bleeding viable bone and rigidly fixed (Fig. 41.3) with T plates or pinning and casting.

Scaphoid Nonunion

Scaphoid nonunions commonly present late with varying degrees of osteolysis, avascular necrosis, collapse, or carpal instability. If the bone has retained its anatomic contours, the treatment is surgical. Through a volar or dorsal approach, the nonunion is curetted and packed with cancellous bone from the distal radius, olecranon, or iliac crest. Self-compressing screws are rarely available, but two parallel K-wires are effective. Pins are removed at 6–8 weeks, and thumb spica casting is continued for another 6–12 weeks.

Femoral Neck Nonunion

Established nonunions of femoral neck fractures are usually painful and disabling. A cementless hemiprosthesis is the best option. If fluoroscopy is available, percutaneous fixation with screws can be attempted in minimally displaced, relatively “fresh”—less than 3 months—fractures in younger individuals, but one should expect a high failure rate.

The only other option is an open reduction with or without internal fixation under direct vision or with fluoroscopy. The anterior approach is less likely to compromise the femoral head’s vascular supply and should be used if only internal fixation is planned.

A posterior approach is needed if one plans to add a corticocancellous pedicle bone graft based on the quadratus femoris muscle (Judet or Meyers procedure) to the internal fixation [2]. In this procedure the femoral insertion of the quadratus femoris is exposed and osteotomized to include a segment of the intertrochanteric crest proximal to the quadratus insertion. The posterior hip capsule is T’ed open, the nonunion exposed, and fibrous tissue curetted from the nonunion site, creating a trough across the nonunion. The defect is filled with cancellous iliac bone chips, and the graft is rotated on its muscle pedicle to cover the defect. It can be secured with a single screw. Internal fixation of the femoral neck is achieved with two or three parallel, short-threaded 6.5 cancellous screws inserted in compression under direct vision from below the greater trochanter. The head can be temporarily pinned to the acetabulum with a Steinmann pin or drill bit, to avoid “spinning” during tapping or screwing. Six-week non-weight-bearing is followed by progressive weight-bearing as tolerated. This procedure is technically easier than it sounds, provides the added advantage of a vascularized graft, and is best reserved for younger patients. Although intuitively appealing, no long-term outcome data exist from resource-poor environments.

Another option is a 15–25° valgus osteotomy at or below the lesser trochanter, fixed in compression with a 135° blade plate, a DHS, or even a well-contoured large fragment DC plate (the straight plate can be bent through the fourth or fifth hole to become a blade plate). The procedure is much easier with fluoroscopy.

Femoral Shaft Nonunion

Nonunions with minimal or no shortening can be exposed by sharply elevating a cortico-periosteal flap anteriorly and laterally, disrupting as little as possible the linea aspera posteriorly (Judet’s osteoperiosteal decortication). Excising all fibrous tissue, the two ends of the intramedullary canal are reopened and internally fixed with a statically locked IM nail (our preference), a dynamic nail with good three-point fixation (Fig. 41.4), or a compression plate (Fig. 41.5).

Bone grafting is mandatory for oligotrophic and atrophic nonunions with generous amounts of cancellous bone packed under the cortico-periosteal flap (Fig. 41.6). Hypertrophic nonunions most often heal with rigid fixation only, avoiding graft donor site morbidity.

Infected nonunions are appearing with increasing frequency after failed ORIF. The infection is addressed by a thorough debridement, removal of hardware if present and loose, along with sequestrectomy to remove all nonviable bone and avascular segments. Hardware that is solid and still contributing to stability can be retained, until there is enough bone healing to allow it to be safely removed. Every effort should be made to mechanically remove as much of the biofilm as possible. Antibiotic beads or spacers can be made with 1.2 g of tobramycin, 2 g of vancomycin, or 6–80 ml vials of gentamicin per batch of cement (any heat-stable antibiotic singly or in combination can be used). Dead space closure and bone coverage with healthy thigh muscle are usually possible.

Another option is temporary stabilization with an external fixator, while the wound is left open to granulate from within. The wound is reassessed at 6 weeks, and if clean, the nonunion site is bone grafted and internally fixed. Suspicious fixator pin tracts should be curetted, the patient put at bed rest, possibly in traction for 7–10 days, and treated with antibiotics before internal fixation.

Chronically infected femoral nonunions represent a formidable challenge. They occur most commonly after an open road or ballistic injury, often after one or more failed attempts at fixation and almost always associated with damage to the surrounding soft tissues. CT or MR imaging and a reliable microbiology lab are useful for diagnosis and treatment planning, but rarely available. Most often the diagnosis relies on history, clinical examination, and plain X-rays. The treatment has two goals: eradication of the infection and consolidation of the nonunion, in that order (see Chap. 31, Chronic Osteomyelitis in Children—the same principles apply).

The first goal is achieved with a wide excision of the infected segment through non-infected tissues and bone, similar to oncologic resection. This is not always easy to determine. The cuts should be through bleeding bone, thus with the tourniquet deflated (beware: blood loss can be significant. Do not attempt without a blood bank). The remaining bone can be managed in one of two ways: external fixation and bone transport [3] or internal fixation and the induced membrane technique of Masquelet [4] (https://​www.​youtube.​com/​watch?​v=​cYc2peeotAM).

Treating long bone infections by either of these techniques is time consuming and can take many months to conclude treatment. Appropriate orthopedic monitoring by a qualified surgeon is mandatory throughout the process; otherwise it should not be started. The authors have no experience with bone transport for this indication, and thus only the induced membrane technique will be described.

Induced Membrane Technique

If using external fixation to stabilize the bone during the first stage, it is prudent to apply it, at least partially, before bone resection, to maintain length. The size of the resection in this first stage is determined as above by clinical signs unless one has access to advanced imaging or a reliable lab and is limited only by the amount of bone graft available for the second stage. Although it is often cited that results are progressively less dependable with resections greater than 5 cm, we have seen successful unions with up to 20 cm resection. Be aware of available graft limitations from previous graft harvesting or significant osteoporosis. The bone defect is filled with a cylinder of cement of equal diameter, capping the exposed bone ends for 1–2 cm. Although Masquelet himself does not incorporate antibiotics in the cement, we still use a combination of vancomycin and tobramycin or gentamicin and have not seen untoward effects.

Other than ex fix or traction after resection of the diseased bone, a cement nail can be used to stabilize the bone without the potential pin tract problems of external fixation (see Box 41.1).

The spacer is left 6–8 weeks, during which time a biologically active membrane forms. Ten to fourteen days before proposed spacer removal and bone graft, remove the ex fix and curettage the pin sites. If microbiology is available, bone specimens from the tip of each stump and pin site curettings should be cultured. Immobilize the extremity with a splint, cast, skeletal traction, or new, temporary ex fix. If the cultures are positive, stage 1 must be repeated in full with a thorough debridement a new spacer and immobilization. If the cultures are negative, the second stage consists of sharply and carefully opening the membrane; removing the spacer, or the spacer and cement nail; and gently inserting the definitive internal fixation (we prefer a nail to a plate) paying particular attention to not damaging the membrane. The gap is filled with bone graft, usually autogenous (see Appendix 3). The wound is closed, and a thick fluffy dressing is applied as drainage is expected for the first 2–3 days.

In the best-case scenario, sequential X-rays will show progressive consolidation, without clinical evidence of wound healing problems or recurrence of the infection. Minor and major complications are common, and the patient needs to know from the onset that amputation may be the final outcome. Most patients will say they understand and agree, but when the surgeon says that amputation is the only remaining option, many patients will not consent. This, a particularly troublesome problem when the patient is between stages, still has a spacer and an ex fix that will sooner or later fail (Figs. 41.7 and 41.8).

The induced membrane technique also has a place in acute, non-infected situations of bone loss greater than 5 cm. The same principles apply of staged preparation of an osteoinductive bed by means of a cement spacer, often over a locked IM nail. In such cases, we usually use antibiotics in the cement because of the extent of associated soft tissue damage. We usually prepare both anterior pelvises for bone graft harvest and have on occasion taken from all four pelvic sites.

Nonunion of Fractures About the Knee

Displaced fractures of the distal femur, proximal tibia, or patella lead to premature degenerative joint disease if not adequately reduced and securely held. They are commonly associated with ligamentous injuries, compounding the problem. The decision to intervene surgically is based on the age and condition of the patient, activity level, time since injury, degree of comminution, amount of displacement, safety of the surgical environment, implant availability, and, importantly, the surgeon’s experience. Older fractures with already existing signs of degenerative arthritis are best left alone until symptoms are severe enough to warrant joint replacement or fusion.

Nonunion of the femoral condyles or tibial plateau is usually painful with weight-bearing. A single large, undisplaced fragment can be fixed in situ with compression screws. With displacement greater than 2 mm, the fragment should be mobilized, reduced, and fixed, with supporting bone graft if needed, but only if the fragments can be reduced and fixed anatomically. A neutralization plate can improve the rigidity and allow early motion. Weight-bearing is avoided for at least 6 weeks.

Meniscal lesions should be properly addressed. Ligamentous reconstruction beyond simple repair has a high risk of failure due to stiffness. Unless the secondary stabilizers—quadriceps and hamstrings—are also significantly damaged, most patients will develop satisfactory compensatory mechanisms with directed therapy.

Nonunion of the patella is addressed only if symptomatic. Occasionally a displaced, non-comminuted transverse fracture nonunion will benefit from mobilization, reduction, and fixation with tension banding or compression screws. Small, comminuted polar fragments can be excised and the patellar or quadriceps tendon reattached with heavy non-resorbable transosseous sutures. Some degree of residual stiffness and/or weakness will remain. Patellectomy may be the only solution to manage disabling pain, but weakness with running and stair climbing and an extension lag is almost unavoidable despite meticulous soft tissue reconstruction.

Nonunion of Tibia/Fibula Shaft Fractures

Nonunions that are not infected are approached in the same way as those in the femur (Fig. 41.9). With stable internal fixation with an IM nail, immediate weight-bearing is encouraged, even if only partial. Some surgeons routinely perform a fibular osteotomy (our preference), but this is not universally accepted (Fig. 41.10). Oligotrophic and atrophic nonunions are bone grafted. Shortening of both segments should not exceed 1–1.5 cm. For nonunions near the ankle, a posterolateral approach is preferred to preserve the local blood supply.

Infected Tibial Nonunions

In resource-poor environments , management of an infected tibial nonunion commonly involves multiple surgical procedures over a long period of time. The many constraints of this approach should be carefully weighed, and the patient made aware of the prolonged and costly process. The first objective in treating an infected, ununited tibial fracture is to control the infection (see Chap. 31, Chronic Osteomyelitis in Children—the same principles apply).

To address instability after debridement of infected bone, the main fragments should be stabilized with an external fixator, a bivalved or windowed cast, or traction through the distal tibia or calcaneus. A saucerized bone that retains two-thirds of its circumference does not need to be stabilized if the patient is compliant with non-weight-bearing. Depending on the available resources and expertise, the wound can be managed open or closed.

Closed management after debridement is with bone graft and wound closure. If bone loss is greater than 3–5 cm, we suggest the induced membrane technique of Masquelet as described above. Though surgical wounds after debridement on the femur in stage 1 can often be closed primarily, the problem in the tibia is soft tissue coverage on these often multi-operated legs, particularly over the distal half. The surgeon needs knowledge of basic flaps: fasciocutaneous, gastrocnemius, soleus, perforator, and cross-leg flap. A healed flap can safely be elevated in its entirety at 6–8 weeks to proceed to stage 2. The medial gastrocnemius works well for nonunions in the proximal third of the tibia and the soleus for the middle third. Wounds needing a soleus flap are often caused by high-energy trauma, with devitalization of the soleus, making this generally less reliable than a gastrocnemius muscle flap. Distal third tibial nonunions remain a problem, as free flaps are rarely available. Fasciocutaneous flaps provide soft tissue coverage throughout the tibia except around the ankle. They do not bring in as robust a blood supply as a transposed muscle, but are easier for the less experienced surgeon. Cross-leg flaps in patients under 25–30 years, reverse sural artery flaps, perforator flaps, and other local flaps are options for those experienced (see Chap. 14).

The open technique of bone grafting as described by Papineau [5] (Box 41.2) is primarily used in tibial bone loss or nonunion. He believed that the mechanical action of direct irrigation in the show promoted healthy granulation tissue and saw no difference in infection rates when comparing clean but non-sterile shower water with sterile saline for irrigation. When the skin and underlying soft tissues are healed and X-rays demonstrate sufficient bone consolidation, usually 4–8 weeks after skin grafting, the fixator is replaced with an above-knee or patellar tendon-bearing cast. Progressive, protected weight-bearing continues until clinical and radiographic consolidation is present. A fibular osteotomy is considered if there is varus drift or no progress to consolidation after 3 months. In open wound techniques, local negative pressure systems, honey, sugar, or papaya paste have been described, with varying degrees of success.

Another approach to managing infected tibial fractures in the pediatric or young adult population is to bypass the infected region by a tibiofibular synostosis proximal and distal to it (Fig. 41.11). This procedure is done through a posterolateral (Harmon) approach with the patient in a lateral or prone position, giving access to the posterior iliac crest where bone graft is harvested. This approach is useful when extensive anterior tibial soft tissue debridement is necessary to address the infection, when a large bone defect is present, and/or when bone transport is not available. After the grafting, a non-weight-bearing above-knee cast is applied and replaced at 6–8 weeks with a weight-bearing AK cast, a patellar tendon-bearing cast, or brace that allows the intact fibula and adjacent bone graft to hypertrophy over the course of 12–24 months until full weight-bearing commences.

Nonunion of Fractures About the Ankle

Intra-articular fractures of the distal tibia, or malleolar fractures, are common and often present late (Fig. 41.12). Patients assume the injury was a “bad sprain” and resume weight-bearing as pain allows or are treated by a local healer and inadequately immobilized. In both scenarios, premature weight-bearing tends to displace the fracture in the direction of the initial injury, most commonly in pronation and external rotation.

The goal of treatment is to reposition the talar body anatomically under the distal tibia, before secondary degenerative changes commence. Because residual displacement dramatically alters the area of contact in the tibiotalar joint, degenerative changes can occur rapidly, making a short window of opportunity for effective treatment. The absence of pain usually means that the young fracture has consolidated, but if pain is present, it is often difficult to determine if it is due to residual motion at the fracture site or synovitis from early articular cartilage wear. Any suspicion that there is motion at the fracture sites can be confirmed with fluoroscopy, stress X-rays, or differential anesthetic blocks.

Some malleolar and pilon fractures that are less than 8–10 weeks should be treated with open reduction and internal fixation (Fig. 41.13). Pilon fractures that are simple, with one large fragment involving more than one-third of the articular surface, displaced more than 2 mm, and have no evidence of advanced consolidation on X-rays can be fixed with compression screws and/or plates. All other late pilon fractures are best handled non-operatively, with treatment focused on functional rehabilitation and surgery most likely a fusion.

Symptomatic undisplaced malleolar nonunions can be treated with compression fixation in situ by screws or plates. Displaced nonunions should be mobilized, reduced, and fixed so the talus sits as anatomically as possible under the distal tibia. In bimalleolar injuries, both malleoli must be mobilized and fixed to achieve this goal. Postoperative deforming forces can be temporarily neutralized by a sturdy Steinmann pin drilled from the calcaneus through the talus and into the distal tibia. The pin is left protruding at the plantar aspect of the heel and protected with a non-weight-bearing below-knee cast and removed after 6–8 weeks. Such pins should be used only in patients who can understand and comply with the non-weight-bearing status.

Malunions

Malunion of the Proximal Femur and Shaft

Osteotomy for malunion should be considered if the mechanical axis deviates by more than 10° in the frontal plane and 15° in the sagittal plane. Malrotation is more difficult to assess, but more than 15–20° of a rotational difference compared to the opposite side should probably be corrected. Deformities are usually multi-planar, requiring a comprehensive physical exam with a detailed understanding of the problem for surgical planning (Fig. 41.14).

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