• Manipulation under anaesthesia (MUA) for frozen shoulder (FS) leads to a considerable increase in range of motion and Oxford shoulder score, a significant reduction in pain and around 85% satisfaction.

• A clearly defined indication for MUA in FS patients cannot be extracted from this review or the available literature. The associating criteria before proceeding to MUA vary widely.

• All but one study in this review lacked a control group without intervention. Therefore, firm conclusions about the role of MUA in the treatment of FS cannot be drawn from the current literature.

• An overall complication rate of 0.4% was found and a re-intervention rate of 14%, although most of the included papers were not designed to monitor complications.

• The following criteria before proceeding to MUA are proposed: a patient unable to cope with a stiff and painful shoulder; clinical signs of a stage 2 idiopathic FS; lessening pain in relation to stage 1; external rotation < 50% compared to contralateral shoulder joint; a minimal duration of symptoms of three months; and failure to respond to an intra-articular corticosteroid infiltration.

Cite this article: EFORT Open Rev 2019;4:98-109. DOI: 10.1302/2058-5241.4.180044

• Total hip arthroplasty is performed more frequently in younger patients nowadays, making long-term bone stock preservation an important topic. A mechanism for late implant failure is periprosthetic bone loss, caused by stress shielding around the hip stem due to different load distribution. Short stems are designed to keep the physical loading in the proximal part of the femur to reduce stress shielding. The aim of this review is to give more insight into how short and anatomic stems behave and whether they succeed in preservation of proximal bone stock.

• A systematic literature search was performed to find all published studies on bone mineral density in short and anatomic hip stems. Results on periprosthetic femoral bone mineral density, measured with dual-energy X-ray absorptiometry (DEXA), were compiled and analysed per Gruen zone in percentual change.

• A total of 29 studies were included. In short stems, Gruen 1 showed bone loss of 5% after one year (n = 855) and 5% after two years (n = 266). Gruen 7 showed bone loss of 10% after one year and –11% after two years. In anatomic stems, Gruen 1 showed bone loss of 8% after one year (n = 731) and 11% after two years (n = 227). Gruen 7 showed bone loss of 14% after one year and 15% after two years.

• Short stems are capable of preserving proximal bone stock and have slightly less proximal bone loss in the first years, compared to anatomic stems.

Cite this article: EFORT Open Rev 2021;6:1040-1051. DOI: 10.1302/2058-5241.6.210030

• Stemless shoulder arthroplasty relies solely on cementless metaphyseal fixation and is designed to avoid stem-related problem such as intraoperative fractures, loosening, stress shielding or stress-risers for periprosthetic fractures.

• Many designs are currently on the market, although only six anatomic and two reverse arthroplasty designs have results published with a minimum of two-year follow-up.

• Compared to stemmed designs, clinical outcome is equally good using stemless designs in the short and medium-term follow-up, which is also the case for overall complication and revision rates.

• Intraoperative fracture rate is lower in stemless compared to stemmed designs, most likely due to the absence of intramedullary preparation and of the implantation of a stem.

• Radiologic abnormalities around the humeral implant are less frequent compared to stemmed implants, possibly related to the closer resemblance to native anatomy.

• Between stemless implants, several significant differences were found in terms of clinical outcome, complication and revision rates, although the level of evidence is low with high study heterogeneity; therefore, firm conclusions could not be drawn.

• There is a need for well-designed long-term randomized trials with sufficient power in order to assess the superiority of stemless over conventional arthroplasty, and of one design over another.

Cite this article: EFORT Open Rev 2021;6:35-49. DOI: 10.1302/2058-5241.6.200067