Costochondral grafts are widely used non-vascularized for the treatment of craniofacial defects, especially the reconstruction of the temporomandibular joint, concha, nose, and trachea (1, 2). Larger bone defects benefit from reconstruction with vascularized bone grafts as bony healing is improved both in quality and time. The same applies to bone healing in poorly vascularized tissue environment or infection (3).

Due to its reliability and rapid reestablishment of skeletal stability which enables earlier rehabilitation of motion, vascularized bone grafting seems especially beneficial in the upper extremity (4). A spectrum of other treatment options for promotion of boney healing in the upper extremity have been proposed in the literature. These options range from local pedicled flaps to non-vascularized distant grafts and other vessels to promote bone healing like platelet-rich plasma (5–7). The results of all techniques vary strongly and are dependent on multiple factors, including surgeon experience and -preferences.

Non-vascularized use of costochondral grafts in the upper extremity has been described for osteoarthritis of the trapeziometacarpal joint, reconstruction of the radial head and the scaphoid (8–10). Application of a vascularized costochondral graft for reconstruction in the upper extremity was described only scarcely for reconstruction of the scaphoid and an ulnar defect (11–13).

We detail the technique of vascularized costochondral graft harvest, its indication for defect reconstruction and outcomes demonstrated by three cases.

Our first case concerns a 62-year-old physically very active male, who presented with pain and restricted range of motion in the third metacarpophalangeal (MCP) joint due to a cartilage defect linked to Mauclair's or Dieterich's disease, a relatively uncommon occurrence of avascular necrosis affecting the metacarpal head (16, 17). The patient was specifically bothered by the inability to perform a full fist closure. Previous cancellous bone grafting in the metacarpal head yielded unsatisfactory outcomes. Upon evaluation in our clinic, a CT and magnetic resonance imaging (MRI) revealed a cartilaginous metacarpal head defect measuring seven by four millimeters, with a two-millimeter joint depression, while the cartilage of the base of the proximal phalanx was deemed adequate (Figures 3 and 4). We discussed various treatment possibilities with the patient, who preferred non-prosthetic options. Considering non-vascularized bone grafting had previously proven ineffective for pain relief in this case, we decided together with the patient to perform an autologous reconstruction involving a contralateral free vascularized costochondral graft. The graft was prepared as outlined above. It included a lateral pedicle and was inserted into the metacarpal head through a tunnel, drilled from the dorsal metacarpal shaft to the defect, which was planned preoperatively guided by the CT imaging (Figures 5 and 6). The refinement of the graft was accomplished by arthroscopically, by shaving the cartilaginous segment. The microsurgical anastomosis was conducted from the intercostal artery to the intermetacarpal artery of the second commissure. The patient exhibited a remarkable recovery, returning to his regular activities including his professional capacity in a supervisory role and golfing in just three months. A subsequent 16-month follow-up revealed the patient's satisfaction with minimal residual stiffness during forceful hyperextension and power grip. Despite a 10 degrees flexion deficit in the MCP joint, the patient enjoyed uninhibited range of motion and full fist closure. Notably, grip strength on both hands measured 50 kilograms, while pinch strength on the affected digit stood at four kilograms, compared to six kilograms on the contralateral side. No signs of osteoarthritis were noted in the follow up x-rays on which the graft was clearly visible without ossifications at one year follow-up (Figure 7).

Our second case concerns a 38-year-old male had a history of a proximal scaphoid fracture three years prior, treated with percutaneous screw fixation. Unfortunately, non-union development and loosening of the screw prompted intervention. After removal of the screw and arthroscopic debridement of cysts, transient relief was achieved. However, upon resuming his usual activities as a laboratory device installer, pain complaints resurfaced due to a proximal pole ischemia, which was confirmed by MRI. The patient was informed about various reconstructive alternatives, including a medial femur condyle osseocartilaginous graft, partial arthrodesis and prosthetic options. Given his age and active lifestyle, primary arthrodesis and prosthesis were ruled out. Moreover, the patient declined a medial femur condyle graft due to concerns about potential knee pain as a passionate recreational soccer player. Consequently, the option of reconstructing the proximal scaphoid with a contralateral free vascularized costochondral graft was discussed and agreed upon. The procedure entailed utilizing a vascularized costochondral graft harvested from the fifth rib on the right side harvested on the medial pedicle, fixated to the scaphoid of the contralateral left wrist using two Kirschner wires and a Linscheidt wire allowing for the scapho-lunate (SL) interosseous ligament to heal after reattachment. The SL ligament could be fixated on the graft by a remaining flake on the ligament. A microsurgical anastomosis between the intercostal artery and the palmar branch of the radial artery was accomplished despite minimal mismatch. Postoperatively, the Kirschner wires were removed at the three-month mark after progressive bony healing, and mobilization was initiated. However, rehabilitation highlighted the graft's size discrepancy, which was corrected through arthroscopic shaving. This adjustment ultimately led to an acceptable range of motion—30 degrees of extension and 40 degrees of flexion. The patient successfully returned to an adapted occupational role after five months. Long-term follow-up showed good integration and stability of the costochondral graft despite a new fall and a first metacarpal fracture two-and-a-half years postoperatively, which could be treated non-operatively.

In our third case a 23-year-old male sustained a dorsal impression fracture of the third metacarpal head when attempting to strike a boxing ball in a festival machine (Figure 8). Due to his young age and physically demanding job on a building site, the patients’ main concern was pain and future osteoarthritis. Initial treatment was non-operative, with a subsequent improvement in active range of motion as swelling subsided. However, a painful clicking sensation emerged during joint movement. MRI confirmed intact base cartilage of the proximal phalanx. Considering these findings, a decision was made to reconstruct the metacarpal head using a contralateral free vascularized costochondral graft. The defect was visualized during the operation (Figure 9), after which, the graft was anchored to the remaining metacarpal using one-and-a-half millimeter cortical screws (Figure 10), with a microsurgical anastomosis linking the lateral intercostal artery to the second dorsal intermetacarpal artery, both of similar caliber. Postoperative management included initial cast immobilization, transitioning to a relative motion splint after two weeks. During the first phase of rehabilitation, a slight clicking of the joint occurred, which also disappeared spontaneously after further mobilization under guidance of the occupational therapists. Range of motion and strength is satisfactory (Figures 11 and 12), but due to his age the patient decided to pursue further education with the goal of obtaining a less physically demanding occupation in the future.

Our case series demonstrates good results of the free vascularized costochondral graft technique for reconstructions in upper extremity surgery. All patients could rehabilitate to satisfaction and reintegrate in daily personal and work environment. Although the range of motion reached was not completely normalized, none of the patients were hindered in daily life. In addition, all patients could reach a stable state of functionality of the hand without any pain. Subjectively, all patients were very satisfied with the results and would undergo the same procedure in the same situation again. Costochondral bone healing was uneventful and rapid in all cases, despite challenging environment of the osteosynthesis.

Most research in vascularized reconstructions in hand surgery have been performed on scaphoid non-union cases and show benefits from vascularized grafts (18–20). Larger osseocartilaginous grafts are usually harvested from the second metatarsal phalangeal (MTP) joint or from the medial femur condyle (MFC), smaller grafts can also be harvested from the hamate. Disadvantages include potential functional donor site morbidity with reduced weight bearing capacity and/or reduced strength as well as persisting complaints and the possibility of premature osteoarthritis. In the literature, donor site complication rates for MFC grafts of 18% are described (21), and for the MTP joint graft, floppy and unstable toes with visible deformities have been described in up to 100% of cases (22). The expected range of motion after reconstructions using these techniques is described between half and two-thirds of the normal range of motion, depending on the anatomical location of the reconstruction. In comparison to these donor sites, the advantage of the costochondral graft would be the hidden scar, in women even in the inframammary fold. The disadvantage is the risk of intraoperative respiratory complications like a pneumothorax and postoperative breathing discomfort and/or development of pneumonia. The symptoms postoperatively are comparable to those of a fractured rib. However, after six weeks, none of our male patients reported any persisting complaints concerning the respiratory tract and none had complications such as a pneumothorax or pneumonia. None was concerned by the aesthetics of the scar on the chest.

Our series show the results of two patients with a metacarpal head reconstruction and one with a scaphoid reconstruction. Both patients with the reconstructions of the metacarpal head were treated using a relative motion splint after wound healing. This facilitated early mobilization to prevent full stiffness after bone consolidation. This strategy was successful in that, after three months both patients reached a full fist closure and were very satisfied with comfort during the rehabilitation period. The patient with the scaphoid reconstruction was immobilized using a plaster cast until one consolidation, due to the healing process of the SL ligament and the wrist dynamics.

Different techniques and levels of rib cartilage donor sites have been described, for example, the fifth, the sixth rib (9, 12) and the seventh rib (23). We prefer the fifth rib due to a good cartilaginous part and an easier approach at the cranial end of the rectus abdominis muscle.

After transplanting a graft from its original position to its new function, the environment changes. The influence of the new vascularization, pressure and movement can lead to changes in density of the graft. Where it started as a chondral graft, it is possible that calcification occurs. This form of ossification consists of a complex sequence of proliferation, differentiation, and tissue remodeling events and comprises multiple distinct steps of late cartilage differentiation. Each of the steps is subject to positive and negative control by environmental signals. Some form of calcification is inevitable, however, care should be taken to prevent full ossification of the graft, as the cartilaginous part is important for joint reconstructions (14, 24). In our series, fortunately, we did not encounter full or any problematic ossification of the graft up until a follow-up of at least one year.

Recently, vascularization is thought to be also important for smaller bone defects, to allow for faster bone healing and motion rehabilitation (4). Moreover, in patients with compromised soft tissues or infection, vascularization is an absolute necessity. Immediate perfusion of the transplanted graft is thought to promote primary bony healing instead of secondary healing, which takes significantly more time and is more prone to delayed- or non-unions.

Despite the positive results from our first experience using this technique, our number are small, which is a limitation in the formation of definitive conclusions. Further research into the technique is warranted to proof reliability. Also, the long-term ossification risk and its prevention should be further investigated. Optimally, a study including a control group using other reconstructive techniques and a correct sample size calculation should be performed. Main objective would be to prevent ongoing osteoarthritis due to joint destruction in young and employed patients, in which case salvage options should be avoided.

Our case series demonstrates the feasibility of vascularized osseocartilaginous bone grafting from the rib with satisfactory clinical results from the subjective patients’ perspective as well as objective measurements. The results allowed all patients to resume their activities of daily life and to a large extend their employment. Larger case series are warranted to proof the reliability and further potential pitfalls of the technique.