The indication for using microfracture technique in the hip is lesions with size less than 2 cm². The MFX technique is same as for other joints. A debridement is first performed in order to produce a defect with vertical walls and a clean bony bottom. Insertions of the instruments are aided by the use of a slotted cannula. Higher degree angle-tipped awls (i.e. up to 90°) are used. Holes are prepared to 2–4 mm depth and 3–5 mm apart. Recently, a modification of the microfracture technique has been presented where 1 mm thick needles are used to be drilled deeper down in the subchondral bone. The technique is called nano-drilling or nano-fracture and the depth will be down to 9 mm and otherwise same management as with simple microfracture technique [10]. In defects between 2 and 3 cm or after failed simple bone marrow stimulation, an augmented bone marrow stimulation technique may be used.

Karthikeyan et al. [36] report that 20 patients who underwent arthroscopic surgery for FAI had a localized full-thickness acetabular chondral defect treated by microfracture and then underwent a later second-look hip arthroscopic procedure. The size of the full-thickness defect was measured at the primary arthroscopic procedure. At an average follow-up of 17 months, 19 of the 20 patients had a mean fill of 96 ± 7 % with macroscopically good-quality repair tissue. One patient had only a 25 % fill with poor quality repair tissue. Histologically, the tissue was found to be composed of primarily fibrocartilage with some staining for type II collagen in the region closest to the bone. Philippon et al. [51] studied nine patients that underwent revision hip arthroscopy for a variety of procedures after undergoing microfracture for treatment of a full-thickness chondral defect of the acetabulum at primary arthroscopy. The size of the chondral defect was measured during primary arthroscopy, and the percent fill of the defect and repair grade were noted at revision hip arthroscopy. Eight of the nine patients had 95–100 % coverage of an isolated acetabular chondral lesion or acetabular lesion associated with a femoral head lesion, with grade 1 or 2 appearance of the repair product at an average of 20 months follow-up.

The bone marrow stimulation area is covered with a collagen membrane or a hyaluronic acid membrane [23, 42]. Leunig et al. [42] treated six patients with AMIC in the hip between 2009 and 2010. Post-operative Oxford hip scores ranged from 13 to 17, UCLA activity scores ranged from 5 to 10, and MOCART scores ranged from 55 to 75. Also PLGA/polydioxanone membranes have been tested as a possible clinical application [24].

The bone marrow stimulation area is filled with a thermo-stabilizing gel acting as an enhancement of the normal blood clot formation attracting the ingrowth of bone marrow cells. [58]. See also section with the description of operative technique.

Carbon fibres may be used to improve the strength of the ingrowing repair tissue [16]. Carbon rods can be introduced arthroscopically. The carbon rods are an alternative when the lesions are surrounded by thin cartilage as seen in an early osteoarthritis. No published results exist with the carbon implants regarding hip implantations.

Other synthetic porous scaffolds may be used with similar purpose.

Mosaicplasty is a technique typically reserved for open surgery of the hip. There are opportunities to use mosaicplasties when there are very large ostochondral defects.

Girard et al. [27] treated 10 patients for femoral cartilage damage by an osteochondral mosaicplasty of the femoral head through a trochanteric flap with surgical dislocation of the hip. At a mean follow-up of 29.2 months, the autograft plugs were well incorporated at the site of osteochondroplasty in the femoral head with intact cartilage over them and smooth interfaces between articulating bony surface. Similarly Meyers [46] has shown the efficacy of allograft use in the hip for large osteochondral defects and osteonecrosis in young patients.

A few case reports exist on autologous chondrocyte implantation with first- and second-generation ACI. Those reports have been on open surgery [2, 47]. Murakibhavi et al. [47] concluded that the short-term results of ACI for osteochondral lesions of the hip suggest that if good early results are obtained, they are observed to continue for at least 5 years. They also found that there is a high failure rate in those with preoperative cyst formation in the hip.

However, hip cartilage lesion treatment with the 3rd-generation ACI with cell scaffolds like MACI or with cell-seeded grafts like Hyalograft can be completed arthroscopically. Mancini and Fontana [45] reviewed 57 consecutive patients that were treated with the MACI (n = 26) or AMIC (n = 31) technique. Patients were assessed preoperatively and up to 5 years using the MHHS to compare outcomes. The modified Harris hip score continued to improve up to 3 years post-operatively and remained stable over time until the final 5-year follow-up. Statistically significant differences between the groups were not observed. The authors suggest that both arthroscopic MACI and AMIC are relevant procedures to repair medium-sized chondral defects on the acetabular side of the hip found during treatment of femoro-acetabular impingement. Being a one-stage procedure and less expensive, AMIC seemed to be a preferable technique compared to ACI. However, the study was not randomized and the lesions were medium sized.

Field et al. [22] have described the grafting of chondral defects and subchondral cysts of the acetabular socket using a synthetic osteochondral plug. Computed tomography and MRI at 6 months confirmed the stability of the osteochondral plugs and on-going healing. Vundelinckx et al. [65] reported a short-term 6-month follow-up of synthetic plug implantation of caput femoris osteochondral lesions. The HOOS score improved and the patient was satisfied after those short months. No long-term results have been published.

HemiCAP (Contoured Articular Prosthetic) hip resurfacing system has been used in young patients with osteochondral lesions of the caput femoris. However, no long-term results are available [34, 41].