Genetic skeletal disorders constitute a rare and heterogeneous bone diseases often leading to poor quality of life. Several surgical options are available. The surgeon must deal with specific features (bone deformity, previous procedures, abnormal bone quality, stiffness or instability, muscle weakness). The questions concern the feasibility of the procedures and the surgical strategy.

55 patients (26 W, 29 M) were reviewed between 2016 and 2022. The mean age of the patients was 35 years (17–71). The diagnosis included 9 hereditary multiple exostoses, 8 osteogenesis imperfecta, 6 multiple epiphyseal dysplasia congenita, 6 achondroplasia, 4 osteopetrosis, 3 pycnodysostosis, 3 hypophosphatemic rickets, 3 fibrous dysplasia, 2 mucopolysaccharidosis, and 10 miscellaneous. 25 patients were referred for hip problems (40 hips). 4 patients (7 hips) requiring a THA have not been operated (4 planned). 4 patients (6 hips) had a proximal femoral fixation (2 osteotomies, 4 fracture fixations). 17 patients (27 hips) sustained a THA (25 primary, 2 revisions). All of them were operated by one operator, using a posterolateral approach and standard implants (including 7 dysplastic and 2 short stems). No customized implant has been used.

As regard the 27 THAs, the mean follow up was 4.2 years (1–12). The early complications included 2 femoral cracks and 1 femur fracture. There were 2 revisions (1 cup loosening at 2 years, 1 stem loosening at 4 years). No infection nor dislocation occurred. All the patients were satisfied with their treatment and regain some autonomy. 3 THA were considered as unfeasible.

Constitutional bone diseases need a multidisciplinary program of care. The indication for surgery is based on a mutual trust patient/surgeon, a careful evaluation of benefits/risks, and an accurate imaging to anticipate the difficulties. The expected results are a better function and quality of life, and a stability over time.

Fracture risks are the most common argument against the use of Ceramic on ceramic (CoC) hip implants. Question: is ceramic material at risk in case of severe local trauma?

Over a long period, we tried to identify patients with a CoC prosthesis (Ceraver Osteal°)who did sustain a trauma. This was conducted in three different institutions.

Eleven patients were found: 9 males and 2 females aged 17 to 70 years at time of index surgery. Accident occurred 6 months to 15 years after index: one car accident, five motorcycle accident, five significant trauma after a fall, including one ski board accident. Consequences of these trauma were: six fractures of the acetabulum with socket loosening in 4 that needed revision, two femoral shaft fracture, one orifed and one stem exchanged, one traumatic hip dislocation associated to loosening of the socket revised at 10 years, and one traumatic loosening of the socket. Ten had no consequence on ceramic integrity. One experienced a fracture of the patella from a dashboard trauma, a liner shipping was discovered during socket revision 2 years later. This is the only case of possible relation between trauma and ceramic fracture. In a more recent longitudinal study on 1856 CoC prosthesis performed from 2010 to 2021, 29 severe traumas were identified with no consequence on Ceramic material.

From this limited case study, it can be assumed that Pure Alumina Ceramic well designed and manufactured, will not break after a significant trauma.

The goal of the study was to describe the features of the aseptic loosening of the cup in CoC THR and to determine factors that affect the time to revision.

It is a retrospective study including all patients who had a revision of CoC THR for aseptic failure fixation of the cup, between 2007 and 2017. 55 patients (27 women, 28 men) (56 hips) were included in the study. Eight hips (13 %) had also a stem exchange. At the primary T HR, the mean age of the patients was 47.9 years (17–72), 28 press fit cups had screws, the mean diameter of the cup was 51.2 mm (46–62) and the mean inclination was 52° (37–67). Clinical and radiological data were retrospectively recorded by an observer different to the initial operators.

The mean age of the patients at the revision was 55.4 years (26–84). The mean time to revision was 90.1 months (14–240), and was significantly greater in patients aged less than 52 years, in cups without screws and with a 28mm head. The trend curve of the time to cup revision showed a bimodal distribution at three and ten years. 20 cups had migrated (33%). Bone loss was rated type 1 in 41 hips (73.0%), type 2 in 12 hips and type 3 in three hips). The mean diameter of the new cup was 52.3 mm (46–64). It was inferior to that of the initial cup in 26 hips (46.4%). 31 cups were impacted (55.5%) and 25 needed to be cemented (45.5%). No macroscopic wear was detected on the ceramic implant.

Aseptic loosening of the cup in CoC THA does not appear to increase over time, supporting the fact that the failure is unrelated to wear and is not due to a biological mechanism. The occurrence of two peaks of frequency over time may suggest that different mechanisms occur.

Recent studies about hip stability after total hip arthroplasties (THA) concerned differences regarding bearings: ceramic on ceramic (CoC) presenting less dislocations on the long term compared to metal or ceramic on polyethylene. The hypothesis is a difference in the healing process of periarticular tissues, with a stronger fibrous tissue for the first one, and more foreign body reaction, joint effusion with the others.

NMR Imaging of the pelvis showing both hips using novel MR MAVRIC program for metal artefacts suppression, were performed in 10 patients, 15 THA and 2 non-pathological contralateral hips. Eight hips had CoC bearings, 3 of which were impacted cementless bulky ceramic implant, and 5 had a metal back. 7 hips had CoP bearings, 4 of which were cemented.

Native capsules showed a mean thickness of 6.6mm. For CoC bearings, capsule thickness ranged from 7mm to 9.6 mm with a mean thickness of 8mm. For CoP bearings, capsule thickness ranged from 3mm to 8.4mm, with a mean thickness of 6.1mm. Neocapsule appeared clearly in all COC bearings observed, while for CoP, sometimes it was less dense with fatty aspect, 3 hips out of 7 having a very thin capsule under 4mm.

It is possible to observe and quantify new capsule after THR and measure differences although not significant regarding bearings on limited number of samples. More patients might be included, but the tendencies observed here might explain better long term stability in vivo observed with Coc.

Ceramic on ceramic (CoC) Total Hip Replacement revisions give specific problems and no consensus is made on the way to perform it. The aim of this study was to report the results of THA CoC revisions and to identify the specific concerns.

Between April 2007 and May 2016, 50 consecutive revisions have been performed on average 2.8 years after the THA, in 46 patients (28 males, 18 females) at a mean age of 55 years. The main reasons for revision were loosening (34%), pain without loosening (20%), infection (12%), implant breakage (10%), and instability (8%). There were 41 implant revisions, five revisions without implant change (10%) and four revisions for head change (8%). Revisions were performed without bone reconstruction in 68% of hips and with a CoC couple in 83% of hips.

Three patients have died and three were lost to follow up. There were six intraoperative femoral fractures, one early and two late non−recurrent dislocations. Eight hips (16%) had re−revision with implant replacement. At a mean follow-up of 5.5 years, the mean PMA, Harris and WOMAC scores were 14.8, 72 and 23. 80% of patients were satisfied of the procedure and 89% were ready to re-do the surgery if necessary. 16% of hips experienced a noise. There were no complete lucent lines, no osteolysis, and no implant migration. Wear was not measurable. The 6-year survival rate was 82 % and 90 % if the end-point was implant revision for any cause and for fixation failure, respectively.

CoC THA failure mainly affects a young population and occurs early. Failure is not wear-related but possibly related to inadequate technique. It is often possible to perform THA revision without any bone graft, using standard implants and CoC couple, provided the implants are matched.

Between 1990 and 1992, we implanted 71 hybrid alumina-on-alumina hip arthroplasties in 62 consecutive patients under the age of 55 years, with a mean age of 46 years at surgery. There were 56 primary and 15 secondary procedures. The prostheses involved a cemented titanium alloy stem, a 32 mm alumina head, and a press-fit metal-backed socket with an alumina insert. Three patients (four hips) died from unrelated causes. Four hips had revision surgery for either deep infection, unexplained persistent pain, fracture of the alumina head, or aseptic loosening of the socket. The nine-year survival rate was 93.7% with revision for any cause as the end-point and 98.4% with revision for aseptic loosening as the end-point.

The outcome in the surviving patients (50 patients, 57 hips) with a minimum five-year follow-up (mean eight years) was excellent in 47 hips (82.5%), very good in eight (14%), good in one and fair in one. A thin, partial, lucent line, mainly in zone III was present in 38% of the sockets and one socket had a complete lucency less than 1 mm thick. One stem had isolated femoral osteolysis. There was no detectable component migration nor acetabular osteolysis.

This hybrid arthroplasty gave satisfactory medium-term results in active patients. The press-fit metal-backed socket appeared to have reliable fixation in alumina-on-alumina hip arthroplasty. The excellent results using cemented fixation of the stem may be related to the low production of wear debris.

After an allogenic bone-marrow transplant, a vascular necrosis of the femoral head may affect young adults, producing destructive lesions which require hip replacement. We have reviewed 27 consecutive such total hip arthroplasties (THA) at a minimal follow-up of two years. Of these, 20 were primary operations for Ficat (1985) stage-III and stage-IV lesions, and seven were revisions after the failure of previous surgery. The median age at operation was 30 years (17.5 to 44). The prostheses had a cemented, collared titanium-alloy stem, an alumina-alumina joint, and a press-fit socket. Seven had a titanium-alloy metal back and 20 had all-alumina cups of which six had to be cemented.

At an average follow-up of five years, no patient had been lost to follow-up. One had died from septicaemia after two years and another with chronic graft-versus-host disease developed a deep infection 2.5 years postoperatively and had a successful revision. There were no revisions for aseptic loosening. The clinical results on the Merle d’Aubigné and Postel (1954) scale were very good or excellent in 23 hips (88%), good in one and fair in two. Ten hips showed incomplete acetabular radiolucencies less than 1 mm thick, but there were no radiolucent lines around the stems.

We conclude that for these difficult patients THA with ceramic joints and careful technique provides the best short- and medium-term option after the failure of medical treatment.