Retroversion, also referred to as posterior wear of the glenoid, can make resurfacing the glenoid challenging. However, careful pre-operative planning with three dimensional CT scanning can allow central placement of the glenoid component through removal of some of the anterior bone to allow contained placement and secure fixation within the glenoid vault. Since the scapula is not a fixed skeletal structure and moves substantially on the chest wall, the actual degree of posterior wear (retroversion) frequently is the result of extraneous biomechanical forces and structures. For example, the degree of kyphosis and shape of the rib cage can have a substantial impact on the relative position of the glenoid surface as it articulates with the humerus. Attempts to totally equalise this through implant augmentation have not, to date, been shown to be effective, and in some cases can be destabilising. Restoration of enough alignment to place the implant centrally can be achieved without need for augmentation even in some very hypoplastic glenoids. The technique for this straight-forward approach will be presented, including pre-surgical planning, in some cases, patient specific instrumentation, with demonstration of functional outcomes

Purpose. Durable fixation may be difficult to achieve when significant bone loss is present, as it occurs in pelvic sarcoma resection and revision surgery of tumor implants. Purpose of this study was to review clinical results of primary and revision surgery of the pelvis and lower extremity in the setting of severe bone loss following limb salvage procedures for bone sarcoma using modular porous tantalum implants. Method. Retrospective study of 15 patients (nine females, six males) undergoing primary or revision pelvic reconstruction (five patients) or revision surgery of a tumor implant of the hip (five patients), knee (four patients), and ankle (one patient) using porous tantalum implants was undertaken. Reason for the tumor implant was resection of bone sarcoma in 13 cases and tumor-like massive bone loss in the remaining two cases. Cause for revision was aseptic failure (nine patients) or deep infection (six patients); average age at the time of surgery was 31 years (16–61 yrs). Revision was managed in a staged fashion in all the six infected cases. All patients presented severe combined segmental and cavitary bone defects. Bone loss was managed in all patients using porous tantalum implants as augmentation of residual bone stock and associated with a megaprosthesis in eight cases (five proximal femur, two distal femur, one proximal tibia). Average follow-up was 4.5 years for hip/knee implants and 2.5 yrs for pelvic reconstructions (range 1–6.8 yrs). Minimum follow-up of two years was available in 11 cases. Results. Infection recurred in one of the six cases managed for infection, requiring further treatment but allowing retention of the porous tantalum implant. All the patients showed well-fixed and functioning implants at latest follow-up. Conclusion. Porous tantalum has been very successful at early follow-up in patients with severe bone loss following primary and revision tumor-related surgery of the pelvis and lower extremity. Longer follow-up is required to appreciate long-term shortcomings